{
  "title": "Natural Numbers vs Whole Numbers (Whole Numbers) - Grade 6 CBSE",
  "total_questions": 150,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "Which of these is a natural number?", "options": {"A": "0", "B": "-1", "C": "1", "D": "1/2"}, "correct_answer": "C"},
    {"id": 2, "difficulty": "easy", "question": "Which of these is a whole number?", "options": {"A": "0", "B": "-3", "C": "2.5", "D": "1/3"}, "correct_answer": "A"},
    {"id": 3, "difficulty": "easy", "question": "The smallest natural number is", "options": {"A": "0", "B": "1", "C": "-1", "D": "2"}, "correct_answer": "B"},
    {"id": 4, "difficulty": "easy", "question": "The smallest whole number is", "options": {"A": "0", "B": "1", "C": "-1", "D": "2"}, "correct_answer": "A"},
    {"id": 5, "difficulty": "easy", "question": "Which set includes natural numbers?", "options": {"A": "{0, 1, 2, 3...}", "B": "{1, 2, 3, 4...}", "C": "{-1, 0, 1, 2...}", "D": "{...-2, -1, 0, 1, 2...}"}, "correct_answer": "B"},
    {"id": 6, "difficulty": "easy", "question": "Which set includes whole numbers?", "options": {"A": "{0, 1, 2, 3...}", "B": "{1, 2, 3, 4...}", "C": "{-1, 0, 1, 2...}", "D": "{...-2, -1, 0, 1, 2...}"}, "correct_answer": "A"},
    {"id": 7, "difficulty": "easy", "question": "How many whole numbers are between 0 and 5?", "options": {"A": "3", "B": "4", "C": "5", "D": "6"}, "correct_answer": "B"},
    {"id": 8, "difficulty": "easy", "question": "How many natural numbers are between 1 and 5?", "options": {"A": "3", "B": "4", "C": "5", "D": "6"}, "correct_answer": "A"},
    {"id": 9, "difficulty": "easy", "question": "Is 0 a natural number?", "options": {"A": "Yes", "B": "No", "C": "Sometimes", "D": "Always"}, "correct_answer": "B"},
    {"id": 10, "difficulty": "easy", "question": "Is 0 a whole number?", "options": {"A": "Yes", "B": "No", "C": "Sometimes", "D": "Always"}, "correct_answer": "A"},
    {"id": 11, "difficulty": "easy", "question": "Which is not a whole number?", "options": {"A": "0", "B": "10", "C": "-5", "D": "25"}, "correct_answer": "C"},
    {"id": 12, "difficulty": "easy", "question": "Which is not a natural number?", "options": {"A": "1", "B": "100", "C": "0", "D": "50"}, "correct_answer": "C"},
    {"id": 13, "difficulty": "easy", "question": "All natural numbers are whole numbers. True or False?", "options": {"A": "True", "B": "False", "C": "Sometimes", "D": "Cannot say"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "All whole numbers are natural numbers. True or False?", "options": {"A": "True", "B": "False", "C": "Sometimes", "D": "Cannot say"}, "correct_answer": "B"},
    {"id": 15, "difficulty": "easy", "question": "The successor of 0 is", "options": {"A": "-1", "B": "0", "C": "1", "D": "2"}, "correct_answer": "C"},
    {"id": 16, "difficulty": "easy", "question": "The predecessor of 1 is", "options": {"A": "-1", "B": "0", "C": "1", "D": "2"}, "correct_answer": "B"},
    {"id": 17, "difficulty": "easy", "question": "The predecessor of 0 is", "options": {"A": "-1", "B": "0", "C": "1", "D": "2"}, "correct_answer": "A"},
    {"id": 18, "difficulty": "easy", "question": "Which number has no predecessor in whole numbers?", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "A"},
    {"id": 19, "difficulty": "easy", "question": "Which number has no predecessor in natural numbers?", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "B"},
    {"id": 20, "difficulty": "easy", "question": "The set {0, 1, 2, 3, 4, 5} represents", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "Integers", "D": "Rational numbers"}, "correct_answer": "B"},

    {"id": 21, "difficulty": "medium", "question": "What is the sum of first 10 natural numbers?", "options": {"A": "45", "B": "50", "C": "55", "D": "60"}, "correct_answer": "C"},
    {"id": 22, "difficulty": "medium", "question": "What is the sum of first 10 whole numbers?", "options": {"A": "45", "B": "50", "C": "55", "D": "60"}, "correct_answer": "A"},
    {"id": 23, "difficulty": "medium", "question": "The product of any whole number and 0 is always", "options": {"A": "0", "B": "1", "C": "The number itself", "D": "Undefined"}, "correct_answer": "A"},
    {"id": 24, "difficulty": "medium", "question": "The product of any natural number and 1 is always", "options": {"A": "0", "B": "1", "C": "The number itself", "D": "Undefined"}, "correct_answer": "C"},
    {"id": 25, "difficulty": "medium", "question": "Which operation is always possible with natural numbers?", "options": {"A": "Subtraction", "B": "Division", "C": "Addition", "D": "All of these"}, "correct_answer": "C"},
    {"id": 26, "difficulty": "medium", "question": "Which operation is always possible with whole numbers?", "options": {"A": "Subtraction", "B": "Division", "C": "Addition", "D": "All of these"}, "correct_answer": "C"},
    {"id": 27, "difficulty": "medium", "question": "The identity element for addition of whole numbers is", "options": {"A": "0", "B": "1", "C": "-1", "D": "The number itself"}, "correct_answer": "A"},
    {"id": 28, "difficulty": "medium", "question": "The identity element for multiplication of natural numbers is", "options": {"A": "0", "B": "1", "C": "-1", "D": "The number itself"}, "correct_answer": "B"},
    {"id": 29, "difficulty": "medium", "question": "Which property holds for both natural and whole numbers?", "options": {"A": "Closure under subtraction", "B": "Closure under addition", "C": "Existence of additive inverse", "D": "Existence of multiplicative inverse"}, "correct_answer": "B"},
    {"id": 30, "difficulty": "medium", "question": "If a and b are whole numbers, then a - b is always", "options": {"A": "A whole number", "B": "A natural number", "C": "An integer", "D": "Not always a whole number"}, "correct_answer": "D"},
    {"id": 31, "difficulty": "medium", "question": "If a and b are natural numbers, then a - b is always", "options": {"A": "A natural number", "B": "A whole number", "C": "An integer", "D": "Not always a natural number"}, "correct_answer": "D"},
    {"id": 32, "difficulty": "medium", "question": "The commutative property holds for addition of", "options": {"A": "Natural numbers only", "B": "Whole numbers only", "C": "Both natural and whole numbers", "D": "Neither"}, "correct_answer": "C"},
    {"id": 33, "difficulty": "medium", "question": "The associative property holds for multiplication of", "options": {"A": "Natural numbers only", "B": "Whole numbers only", "C": "Both natural and whole numbers", "D": "Neither"}, "correct_answer": "C"},
    {"id": 34, "difficulty": "medium", "question": "Distributive property of multiplication over addition holds for", "options": {"A": "Natural numbers only", "B": "Whole numbers only", "C": "Both natural and whole numbers", "D": "Neither"}, "correct_answer": "C"},
    {"id": 35, "difficulty": "medium", "question": "Which of these is closed under subtraction?", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "Both", "D": "Neither"}, "correct_answer": "D"},
    {"id": 36, "difficulty": "medium", "question": "Which of these is closed under division?", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "Both", "D": "Neither"}, "correct_answer": "D"},
    {"id": 37, "difficulty": "medium", "question": "The set of whole numbers is", "options": {"A": "Finite", "B": "Infinite", "C": "Empty", "D": "Contains only 0"}, "correct_answer": "B"},
    {"id": 38, "difficulty": "medium", "question": "The set of natural numbers is", "options": {"A": "Finite", "B": "Infinite", "C": "Empty", "D": "Contains only 1"}, "correct_answer": "B"},
    {"id": 39, "difficulty": "medium", "question": "Every natural number has a", "options": {"A": "Predecessor", "B": "Successor", "C": "Both", "D": "Neither"}, "correct_answer": "B"},
    {"id": 40, "difficulty": "medium", "question": "Every whole number has a", "options": {"A": "Predecessor", "B": "Successor", "C": "Both", "D": "Neither"}, "correct_answer": "B"},
    {"id": 41, "difficulty": "medium", "question": "The number of whole numbers between 0 and 100 is", "options": {"A": "98", "B": "99", "C": "100", "D": "101"}, "correct_answer": "B"},
    {"id": 42, "difficulty": "medium", "question": "The number of natural numbers between 1 and 100 is", "options": {"A": "98", "B": "99", "C": "100", "D": "101"}, "correct_answer": "A"},
    {"id": 43, "difficulty": "medium", "question": "Which of these is always true for natural numbers?", "options": {"A": "a + b = b + a", "B": "a - b = b - a", "C": "a ÷ b = b ÷ a", "D": "None of these"}, "correct_answer": "A"},
    {"id": 44, "difficulty": "medium", "question": "Which of these is always true for whole numbers?", "options": {"A": "a × b = b × a", "B": "a - b = b - a", "C": "a ÷ b = b ÷ a", "D": "None of these"}, "correct_answer": "A"},
    {"id": 45, "difficulty": "medium", "question": "The additive identity for whole numbers is", "options": {"A": "0", "B": "1", "C": "-1", "D": "Does not exist"}, "correct_answer": "A"},
    {"id": 46, "difficulty": "medium", "question": "The multiplicative identity for natural numbers is", "options": {"A": "0", "B": "1", "C": "-1", "D": "Does not exist"}, "correct_answer": "B"},
    {"id": 47, "difficulty": "medium", "question": "If n is a whole number, then 2n is always", "options": {"A": "Even", "B": "Odd", "C": "Prime", "D": "Composite"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "medium", "question": "If n is a natural number, then 2n + 1 is always", "options": {"A": "Even", "B": "Odd", "C": "Prime", "D": "Composite"}, "correct_answer": "B"},
    {"id": 49, "difficulty": "medium", "question": "Which of these numbers is neither prime nor composite?", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "B"},
    {"id": 50, "difficulty": "medium", "question": "The number 1 is", "options": {"A": "Prime", "B": "Composite", "C": "Neither prime nor composite", "D": "Both prime and composite"}, "correct_answer": "C"},
    {"id": 51, "difficulty": "medium", "question": "The number 0 is", "options": {"A": "Even", "B": "Odd", "C": "Neither even nor odd", "D": "Both even and odd"}, "correct_answer": "A"},
    {"id": 52, "difficulty": "medium", "question": "Which of these is true for all natural numbers n?", "options": {"A": "n > 0", "B": "n ≥ 0", "C": "n ≥ 1", "D": "n > 1"}, "correct_answer": "C"},
    {"id": 53, "difficulty": "medium", "question": "Which of these is true for all whole numbers n?", "options": {"A": "n > 0", "B": "n ≥ 0", "C": "n ≥ 1", "D": "n > 1"}, "correct_answer": "B"},
    {"id": 54, "difficulty": "medium", "question": "The set of whole numbers is a subset of", "options": {"A": "Natural numbers", "B": "Integers", "C": "Rational numbers", "D": "All of these"}, "correct_answer": "B"},
    {"id": 55, "difficulty": "medium", "question": "The set of natural numbers is a subset of", "options": {"A": "Whole numbers", "B": "Integers", "C": "Rational numbers", "D": "All of these"}, "correct_answer": "D"},
    {"id": 56, "difficulty": "medium", "question": "If W represents whole numbers and N represents natural numbers, then", "options": {"A": "W ⊂ N", "B": "N ⊂ W", "C": "W = N", "D": "W ∩ N = ∅"}, "correct_answer": "B"},
    {"id": 57, "difficulty": "medium", "question": "The difference between the set of whole numbers and natural numbers is", "options": {"A": "{0}", "B": "{1}", "C": "{-1}", "D": "∅"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "medium", "question": "Which of these operations is not closed for natural numbers?", "options": {"A": "Addition", "B": "Multiplication", "C": "Subtraction", "D": "All are closed"}, "correct_answer": "C"},
    {"id": 59, "difficulty": "medium", "question": "Which of these operations is not closed for whole numbers?", "options": {"A": "Addition", "B": "Multiplication", "C": "Subtraction", "D": "All are closed"}, "correct_answer": "C"},
    {"id": 60, "difficulty": "medium", "question": "The sum of two odd natural numbers is always", "options": {"A": "Odd", "B": "Even", "C": "Prime", "D": "Composite"}, "correct_answer": "B"},
    {"id": 61, "difficulty": "medium", "question": "The product of two even whole numbers is always", "options": {"A": "Odd", "B": "Even", "C": "Prime", "D": "Composite"}, "correct_answer": "B"},
    {"id": 62, "difficulty": "medium", "question": "If a and b are whole numbers and a + b = a, then b =", "options": {"A": "0", "B": "1", "C": "a", "D": "Cannot determine"}, "correct_answer": "A"},
    {"id": 63, "difficulty": "medium", "question": "If a and b are natural numbers and a × b = a, then b =", "options": {"A": "0", "B": "1", "C": "a", "D": "Cannot determine"}, "correct_answer": "B"},
    {"id": 64, "difficulty": "medium", "question": "The smallest prime natural number is", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "C"},
    {"id": 65, "difficulty": "medium", "question": "The smallest prime whole number is", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "C"},
    {"id": 66, "difficulty": "medium", "question": "Which of these numbers has exactly one factor?", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "B"},
    {"id": 67, "difficulty": "medium", "question": "Which of these numbers has infinite factors?", "options": {"A": "0", "B": "1", "C": "2", "D": "3"}, "correct_answer": "A"},
    {"id": 68, "difficulty": "medium", "question": "The number of factors of 0 is", "options": {"A": "0", "B": "1", "C": "2", "D": "Infinite"}, "correct_answer": "D"},
    {"id": 69, "difficulty": "medium", "question": "The number of factors of 1 is", "options": {"A": "0", "B": "1", "C": "2", "D": "Infinite"}, "correct_answer": "B"},
    {"id": 70, "difficulty": "medium", "question": "If n is a natural number, then n² - n is always divisible by", "options": {"A": "2", "B": "3", "C": "4", "D": "5"}, "correct_answer": "A"},
    {"id": 71, "difficulty": "medium", "question": "If n is a whole number, then n(n+1) is always", "options": {"A": "Odd", "B": "Even", "C": "Prime", "D": "Composite"}, "correct_answer": "B"},
    {"id": 72, "difficulty": "medium", "question": "The sum of first n natural numbers is", "options": {"A": "n(n+1)/2", "B": "n(n-1)/2", "C": "n²", "D": "2n"}, "correct_answer": "A"},
    {"id": 73, "difficulty": "medium", "question": "The sum of first n whole numbers is", "options": {"A": "n(n+1)/2", "B": "n(n-1)/2", "C": "n²", "D": "2n"}, "correct_answer": "A"},
    {"id": 74, "difficulty": "medium", "question": "Which of these sets is finite?", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "Neither", "D": "Both"}, "correct_answer": "C"},
    {"id": 75, "difficulty": "medium", "question": "The number 0 is considered as", "options": {"A": "Positive", "B": "Negative", "C": "Neither positive nor negative", "D": "Both positive and negative"}, "correct_answer": "C"},
    {"id": 76, "difficulty": "medium", "question": "All natural numbers are", "options": {"A": "Positive", "B": "Negative", "C": "Either", "D": "Neither"}, "correct_answer": "A"},
    {"id": 77, "difficulty": "medium", "question": "Which of these numbers is a whole number but not a natural number?", "options": {"A": "0", "B": "1", "C": "-1", "D": "1/2"}, "correct_answer": "A"},
    {"id": 78, "difficulty": "medium", "question": "Which of these numbers is a natural number but not a whole number?", "options": {"A": "0", "B": "1", "C": "-1", "D": "None of these"}, "correct_answer": "D"},
    {"id": 79, "difficulty": "medium", "question": "The intersection of natural numbers and whole numbers is", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "{0}", "D": "∅"}, "correct_answer": "A"},
    {"id": 80, "difficulty": "medium", "question": "The union of natural numbers and whole numbers is", "options": {"A": "Natural numbers", "B": "Whole numbers", "C": "Integers", "D": "Rational numbers"}, "correct_answer": "B"},

    {"id": 81, "difficulty": "hard", "question": "If a, b are natural numbers and a > b, then a - b is always", "options": {"A": "Natural number", "B": "Whole number", "C": "Positive integer", "D": "All of these"}, "correct_answer": "D"},
    {"id": 82, "difficulty": "hard", "question": "For any three whole numbers a, b, c, if a = b and b = c, then a = c. This property is called", "options": {"A": "Commutative", "B": "Associative", "C": "Transitive", "D": "Distributive"}, "correct_answer": "C"},
    {"id": 83, "difficulty": "hard", "question": "The statement 'If a and b are whole numbers, then a + b = b + a' represents", "options": {"A": "Closure property", "B": "Commutative property", "C": "Associative property", "D": "Distributive property"}, "correct_answer": "B"},
    {"id": 84, "difficulty": "hard", "question": "For whole numbers, division by zero is", "options": {"A": "Always 0", "B": "The number itself", "C": "Not defined", "D": "Always 1"}, "correct_answer": "C"},
    {"id": 85, "difficulty": "hard", "question": "The number of whole numbers between n and m (where n < m) is", "options": {"A": "m - n", "B": "m - n - 1", "C": "m - n + 1", "D": "m + n"}, "correct_answer": "B"},
    {"id": 86, "difficulty": "hard", "question": "The number of natural numbers between n and m (where n < m) is", "options": {"A": "m - n", "B": "m - n - 1", "C": "m - n + 1", "D": "m + n"}, "correct_answer": "B"},
    {"id": 87, "difficulty": "hard", "question": "If a, b, c are whole numbers and a × (b + c) = a × b + a × c, this illustrates", "options": {"A": "Commutative property", "B": "Associative property", "C": "Distributive property", "D": "Closure property"}, "correct_answer": "C"},
    {"id": 88, "difficulty": "hard", "question": "The sum of any two consecutive natural numbers is always", "options": {"A": "Even", "B": "Odd", "C": "Prime", "D": "Composite"}, "correct_answer": "B"},
    {"id": 89, "difficulty": "hard", "question": "The product of any two consecutive whole numbers is always", "options": {"A": "Even", "B": "Odd", "C": "Prime", "D": "Composite"}, "correct_answer": "A"},
    {"id": 90, "difficulty": "hard", "question": "For any natural number n, n³ - n is always divisible by", "options": {"A": "2", "B": "3", "C": "6", "D": "All of these"}, "correct_answer": "D"},
    {"id": 91, "difficulty": "hard", "question": "The number of even whole numbers less than 100 is", "options": {"A": "49", "B": "50", "C": "51", "D": "52"}, "correct_answer": "B"},
    {"id": 92, "difficulty": "hard", "question": "The number of odd natural numbers less than 100 is", "options": {"A": "49", "B": "50", "C": "51", "D": "52"}, "correct_answer": "A"},
    {"id": 93, "difficulty": "hard", "question": "If n is a natural number, then the number of natural numbers between n² and (n+1)² is", "options": {"A": "n", "B": "n+1", "C": "2n", "D": "2n+1"}, "correct_answer": "C"},
    {"id": 94, "difficulty": "hard", "question": "The difference between the successor and predecessor of a natural number n is", "options": {"A": "0", "B": "1", "C": "2", "D": "n"}, "correct_answer": "C"},
    {"id": 95, "difficulty": "hard", "question": "The difference between the successor and predecessor of a whole number n (n > 0) is", "options": {"A": "0", "B": "1", "C": "2", "D": "n"}, "correct_answer": "C"},
    {"id": 96, "difficulty": "hard", "question": "If a, b, c are natural numbers and a divides b, b divides c, then", "options": {"A": "a divides c", "B": "c divides a", "C": "a = c", "D": "None of these"}, "correct_answer": "A"},
    {"id": 97, "difficulty": "hard", "question": "The set of whole numbers is closed under which operations?", "options": {"A": "Addition and multiplication only", "B": "Addition, subtraction, multiplication", "C": "All operations", "D": "None of these"}, "correct_answer": "A"},
    {"id": 98, "difficulty": "hard", "question": "The set of natural numbers is closed under which operations?", "options": {"A": "Addition and multiplication only", "B": "Addition, subtraction, multiplication", "C": "All operations", "D": "None of these"}, "correct_answer": "A"},
    {"id": 99, "difficulty": "hard", "question": "For any whole number n, n × 0 = 0 × n = 0. This is because 0 is", "options": {"A": "Additive identity", "B": "Multiplicative identity", "C": "Absorbing element", "D": "Inverse element"}, "correct_answer": "C"},
    {"id": 100, "difficulty": "hard", "question": "The statement 'Every natural number except 1 has at least two factors' is", "options": {"A": "Always true", "B": "Sometimes true", "C": "Never true", "D": "Cannot determine"}, "correct_answer": "A"}
 ,
{"id":101,"difficulty":"easy","question":"Which of the following is a natural number?","options":{"A":"0","B":"-2","C":"3","D":"-5"},"correct_answer":"C"},
  {"id":102,"difficulty":"easy","question":"Which of the following is a whole number?","options":{"A":"-1","B":"0","C":"1/2","D":"-3"},"correct_answer":"B"},
  {"id":103,"difficulty":"easy","question":"Natural numbers start from","options":{"A":"0","B":"1","C":"-1","D":"2"},"correct_answer":"B"},
  {"id":104,"difficulty":"easy","question":"Whole numbers include","options":{"A":"Only positive numbers","B":"0 and positive numbers","C":"Only negative numbers","D":"All integers"},"correct_answer":"B"},
  {"id":105,"difficulty":"easy","question":"Which number is common to both natural and whole numbers?","options":{"A":"0","B":"-1","C":"1","D":"-2"},"correct_answer":"C"},
  {"id":106,"difficulty":"easy","question":"How many natural numbers are there between 2 and 6?","options":{"A":"2","B":"3","C":"4","D":"5"},"correct_answer":"B"},
  {"id":107,"difficulty":"easy","question":"How many whole numbers are there between 0 and 6?","options":{"A":"4","B":"5","C":"6","D":"7"},"correct_answer":"A"},
  {"id":108,"difficulty":"easy","question":"Which is not a natural number?","options":{"A":"5","B":"9","C":"0","D":"12"},"correct_answer":"C"},
  {"id":109,"difficulty":"easy","question":"Which is not a whole number?","options":{"A":"0","B":"7","C":"-4","D":"15"},"correct_answer":"C"},
  {"id":110,"difficulty":"easy","question":"The successor of 9 is","options":{"A":"8","B":"9","C":"10","D":"11"},"correct_answer":"C"},

  {"id":111,"difficulty":"easy","question":"The predecessor of 5 is","options":{"A":"3","B":"4","C":"5","D":"6"},"correct_answer":"B"},
  {"id":112,"difficulty":"easy","question":"Which whole number has no predecessor?","options":{"A":"1","B":"2","C":"0","D":"3"},"correct_answer":"C"},
  {"id":113,"difficulty":"easy","question":"Which natural number has no predecessor?","options":{"A":"1","B":"2","C":"3","D":"4"},"correct_answer":"A"},
  {"id":114,"difficulty":"easy","question":"The set {1,2,3,4,...} represents","options":{"A":"Whole numbers","B":"Natural numbers","C":"Integers","D":"Rational numbers"},"correct_answer":"B"},
  {"id":115,"difficulty":"easy","question":"The set {0,1,2,3,...} represents","options":{"A":"Natural numbers","B":"Whole numbers","C":"Integers","D":"Fractions"},"correct_answer":"B"},
  {"id":116,"difficulty":"easy","question":"Is 0 included in natural numbers?","options":{"A":"Yes","B":"No","C":"Sometimes","D":"Always"},"correct_answer":"B"},
  {"id":117,"difficulty":"easy","question":"Is 0 included in whole numbers?","options":{"A":"Yes","B":"No","C":"Sometimes","D":"Never"},"correct_answer":"A"},
  {"id":118,"difficulty":"easy","question":"All natural numbers are","options":{"A":"Negative","B":"Whole","C":"Integers only","D":"Fractions"},"correct_answer":"B"},
  {"id":119,"difficulty":"easy","question":"All whole numbers are","options":{"A":"Natural numbers","B":"Integers","C":"Fractions","D":"Negative numbers"},"correct_answer":"B"},
  {"id":120,"difficulty":"easy","question":"Which number is neither natural nor whole?","options":{"A":"0","B":"1","C":"-1","D":"2"},"correct_answer":"C"},

  {"id":121,"difficulty":"medium","question":"What is the sum of first 5 natural numbers?","options":{"A":"10","B":"15","C":"20","D":"25"},"correct_answer":"B"},
  {"id":122,"difficulty":"medium","question":"What is the sum of first 5 whole numbers?","options":{"A":"10","B":"15","C":"20","D":"5"},"correct_answer":"A"},
  {"id":123,"difficulty":"medium","question":"The additive identity for whole numbers is","options":{"A":"1","B":"0","C":"-1","D":"None"},"correct_answer":"B"},
  {"id":124,"difficulty":"medium","question":"The multiplicative identity for natural numbers is","options":{"A":"0","B":"-1","C":"1","D":"2"},"correct_answer":"C"},
  {"id":125,"difficulty":"medium","question":"Which operation is always closed for natural numbers?","options":{"A":"Subtraction","B":"Division","C":"Addition","D":"Subtraction and division"},"correct_answer":"C"},
  {"id":126,"difficulty":"medium","question":"Which operation is always closed for whole numbers?","options":{"A":"Subtraction","B":"Division","C":"Addition","D":"None"},"correct_answer":"C"},
  {"id":127,"difficulty":"medium","question":"Which property holds for addition of natural numbers?","options":{"A":"Closure","B":"Commutative","C":"Associative","D":"All of these"},"correct_answer":"D"},
  {"id":128,"difficulty":"medium","question":"Which property does not hold for subtraction of whole numbers?","options":{"A":"Closure","B":"Commutative","C":"Associative","D":"All of these"},"correct_answer":"D"},
  {"id":129,"difficulty":"medium","question":"The set of natural numbers is","options":{"A":"Finite","B":"Infinite","C":"Empty","D":"Limited"},"correct_answer":"B"},
  {"id":130,"difficulty":"medium","question":"The set of whole numbers is","options":{"A":"Finite","B":"Infinite","C":"Empty","D":"Limited"},"correct_answer":"B"},

  {"id":131,"difficulty":"medium","question":"How many natural numbers are there between 10 and 20?","options":{"A":"8","B":"9","C":"10","D":"11"},"correct_answer":"B"},
  {"id":132,"difficulty":"medium","question":"How many whole numbers are there between 10 and 20?","options":{"A":"8","B":"9","C":"10","D":"11"},"correct_answer":"A"},
  {"id":133,"difficulty":"medium","question":"Which of these is always true?","options":{"A":"a + b = b + a","B":"a - b = b - a","C":"a ÷ b = b ÷ a","D":"None"},"correct_answer":"A"},
  {"id":134,"difficulty":"medium","question":"If n is a natural number, then n + 0 is","options":{"A":"0","B":"n","C":"1","D":"n + 1"},"correct_answer":"B"},
  {"id":135,"difficulty":"medium","question":"If n is a whole number, then n × 1 is","options":{"A":"0","B":"1","C":"n","D":"n + 1"},"correct_answer":"C"},
  {"id":136,"difficulty":"medium","question":"Which of the following is true?","options":{"A":"Natural numbers include 0","B":"Whole numbers include 0","C":"Natural numbers include -1","D":"Whole numbers include -2"},"correct_answer":"B"},
  {"id":137,"difficulty":"medium","question":"The difference between whole numbers and natural numbers is","options":{"A":"1","B":"0","C":"-1","D":"No difference"},"correct_answer":"B"},
  {"id":138,"difficulty":"medium","question":"Which number has exactly one factor?","options":{"A":"0","B":"1","C":"2","D":"3"},"correct_answer":"B"},
  {"id":139,"difficulty":"medium","question":"Which number has infinitely many factors?","options":{"A":"0","B":"1","C":"2","D":"3"},"correct_answer":"A"},
  {"id":140,"difficulty":"medium","question":"Which of these is neither prime nor composite?","options":{"A":"0","B":"1","C":"2","D":"3"},"correct_answer":"B"},

  {"id":141,"difficulty":"hard","question":"If a and b are natural numbers and a > b, then a − b is always","options":{"A":"Natural","B":"Whole","C":"Integer","D":"Positive integer"},"correct_answer":"D"},
  {"id":142,"difficulty":"hard","question":"The difference between successor and predecessor of a natural number is","options":{"A":"0","B":"1","C":"2","D":"3"},"correct_answer":"C"},
  {"id":143,"difficulty":"hard","question":"For any whole number n, n(n+1) is always","options":{"A":"Odd","B":"Even","C":"Prime","D":"Composite"},"correct_answer":"B"},
  {"id":144,"difficulty":"hard","question":"If n is a natural number, then n² − n is divisible by","options":{"A":"1","B":"2","C":"3","D":"4"},"correct_answer":"B"},
  {"id":145,"difficulty":"hard","question":"The number of even whole numbers less than 50 is","options":{"A":"24","B":"25","C":"26","D":"27"},"correct_answer":"B"},
  {"id":146,"difficulty":"hard","question":"The number of odd natural numbers less than 50 is","options":{"A":"24","B":"25","C":"26","D":"27"},"correct_answer":"A"},
  {"id":147,"difficulty":"hard","question":"Which set is closed under multiplication?","options":{"A":"Natural numbers","B":"Whole numbers","C":"Both","D":"Neither"},"correct_answer":"C"},
  {"id":148,"difficulty":"hard","question":"Which set is not closed under subtraction?","options":{"A":"Natural numbers","B":"Whole numbers","C":"Both","D":"Neither"},"correct_answer":"C"},
  {"id":149,"difficulty":"hard","question":"If n is a natural number, then (n+1)² − n² equals","options":{"A":"1","B":"2n","C":"2n+1","D":"n"},"correct_answer":"C"},
  {"id":150,"difficulty":"hard","question":"The statement “Every natural number has a successor” is","options":{"A":"False","B":"Sometimes true","C":"Always true","D":"Never true"},"correct_answer":"C"}
 ]
}