{
  "title": "Grouped Data (Data Handling) - Grade 8 ICSE",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "easy",
      "question": "📊 Grouped data organizes data into ___.",
      "options": {
        "A": "lists",
        "B": "classes/intervals",
        "C": "pictures",
        "D": "sentences"
      },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "easy",
      "question": "📈 The range of class 10-20 is ___.",
      "options": {
        "A": "11",
        "B": "10",
        "C": "20",
        "D": "30"
      },
      "correct_answer": "B"
    },
    {
      "id": 3,
      "difficulty": "easy",
      "question": "📊 The mid-point of class 20-30 is ___.",
      "options": { "A": 20, "B": 25, "C": 30, "D": 50 },
      "correct_answer": "B"
    },
    {
      "id": 4,
      "difficulty": "easy",
      "question": "📋 In grouped data, the number of observations in a class is called ___.",
      "options": {
        "A": "range",
        "B": "frequency",
        "C": "mid-point",
        "D": "limit"
      },
      "correct_answer": "B"
    },
    {
      "id": 5,
      "difficulty": "easy",
      "question": "📊 Classes like 0-10, 10-20, 20-30 are called ___ classes.",
      "options": {
        "A": "exclusive",
        "B": "inclusive",
        "C": "overlapping",
        "D": "discrete"
      },
      "correct_answer": "A"
    },
    {
      "id": 6,
      "difficulty": "easy",
      "question": "📈 If a data value is 15, it belongs to class ___. (classes: 10-20, 20-30)",
      "options": { "A": "10-20", "B": "20-30", "C": "both", "D": "neither" },
      "correct_answer": "A"
    },
    {
      "id": 7,
      "difficulty": "easy",
      "question": "📊 The upper limit of class 40-50 is ___.",
      "options": { "A": 40, "B": 45, "C": 50, "D": 90 },
      "correct_answer": "C"
    },
    {
      "id": 8,
      "difficulty": "easy",
      "question": "📋 The class size of 30-40 is ___.",
      "options": {
        "A": "10",
        "B": "11",
        "C": "9",
        "D": "40"
      },
      "correct_answer": "A"
    },
    {
      "id": 9,
      "difficulty": "easy",
      "question": "📊 For class 20-30, the lower class boundary is ___.",
      "options": { "A": "20", "B": "25", "C": "30", "D": "35" },
      "correct_answer": "A"
    },
    {
      "id": 10,
      "difficulty": "easy",
      "question": "📈 A frequency table shows data in ___.",
      "options": {
        "A": "graph",
        "B": "table form",
        "C": "picture",
        "D": "sentence"
      },
      "correct_answer": "B"
    },
    {
      "id": 11,
      "difficulty": "easy",
      "question": "📊 Tally marks |||| |||| represents number ___.",
      "options": {
        "A": "10",
        "B": "8",
        "C": "9",
        "D": "7"
      },
      "correct_answer": "A"
    },
    {
      "id": 12,
      "difficulty": "easy",
      "question": "📋 The difference between upper and lower limit is ___.",
      "options": {
        "A": "mid-point",
        "B": "class size",
        "C": "frequency",
        "D": "range"
      },
      "correct_answer": "B"
    },
    {
      "id": 13,
      "difficulty": "easy",
      "question": "📊 Classes 0-9, 10-19, 20-29 are ___ type.",
      "options": {
        "A": "inclusive",
        "B": "exclusive",
        "C": "continuous",
        "D": "overlapping"
      },
      "correct_answer": "A"
    },
    {
      "id": 14,
      "difficulty": "easy",
      "question": "📈 To find total observations, we add all ___.",
      "options": {
        "A": "limits",
        "B": "frequencies",
        "C": "ranges",
        "D": "mid-points"
      },
      "correct_answer": "B"
    },
    {
      "id": 15,
      "difficulty": "easy",
      "question": "📊 If class is 10-20, 20-30, a value 20 goes in class ___.",
      "options": {
        "A": "20-30",
        "B": "10-20",
        "C": "both",
        "D": "neither"
      },
      "correct_answer": "A"
    },
    {
      "id": 16,
      "difficulty": "easy",
      "question": "📋 The class mark of 50-60 is ___.",
      "options": { "A": 50, "B": 55, "C": 60, "D": 110 },
      "correct_answer": "B"
    },
    {
      "id": 17,
      "difficulty": "easy",
      "question": "📊 In a grouped frequency table, we use ___ to count quickly.",
      "options": {
        "A": "numbers",
        "B": "tally marks",
        "C": "dots",
        "D": "colors"
      },
      "correct_answer": "B"
    },
    {
      "id": 18,
      "difficulty": "easy",
      "question": "📈 If frequency of class 30-40 is 12, it means ___ data points in that range.",
      "options": { "A": 12, "B": 30, "C": 40, "D": 70 },
      "correct_answer": "A"
    },
    {
      "id": 19,
      "difficulty": "easy",
      "question": "📊 The sum of frequencies equals ___.",
      "options": {
        "A": "class size",
        "B": "total observations",
        "C": "range",
        "D": "mid-point"
      },
      "correct_answer": "B"
    },
    {
      "id": 20,
      "difficulty": "easy",
      "question": "📋 For class 15-25, the class width is ___.",
      "options": {
        "A": "11",
        "B": "10",
        "C": "15",
        "D": "25"
      },
      "correct_answer": "A"
    },
    {
      "id": 21,
      "difficulty": "medium",
      "question": "📊 Grouped data: Classes 0-10, 10-20, 20-30. Frequencies: 5, 8, 7. Total observations?",
      "options": {
        "A": "20",
        "B": "18",
        "C": "19",
        "D": "21"
      },
      "correct_answer": "A"
    },
    {
      "id": 22,
      "difficulty": "medium",
      "question": "📈 Data: 12, 15, 18, 22, 25, 28. If classes 10-20, 20-30, frequency for 20-30?",
      "options": { "A": 2, "B": 3, "C": 4, "D": 5 },
      "correct_answer": "B"
    },
    {
      "id": 23,
      "difficulty": "medium",
      "question": "📊 Class intervals: 0-5, 5-10, 10-15. For value 10, which class?",
      "options": { "A": "0-5", "B": "5-10", "C": "10-15", "D": "both B and C" },
      "correct_answer": "C"
    },
    {
      "id": 24,
      "difficulty": "medium",
      "question": "📋 Tally marks: |||| \\|||| ||. Frequency?",
      "options": { "A": 6, "B": 7, "C": 8, "D": 9 },
      "correct_answer": "B"
    },
    {
      "id": 25,
      "difficulty": "medium",
      "question": "📊 Class marks: 25, 35, 45. Class size?",
      "options": { "A": 5, "B": 10, "C": 15, "D": 20 },
      "correct_answer": "B"
    },
    {
      "id": 26,
      "difficulty": "medium",
      "question": "📈 If class 30-40 has frequency 0, it means?",
      "options": {
        "A": "no data in that range",
        "B": "data is missing",
        "C": "error",
        "D": "class is invalid"
      },
      "correct_answer": "A"
    },
    {
      "id": 27,
      "difficulty": "medium",
      "question": "📊 For continuous classes, we use ___ limits.",
      "options": {
        "A": "exclusive",
        "B": "inclusive",
        "C": "overlapping",
        "D": "non-overlapping"
      },
      "correct_answer": "A"
    },
    {
      "id": 28,
      "difficulty": "medium",
      "question": "📋 Class: 20-29, 30-39. Class size?",
      "options": {
        "A": "10",
        "B": "9",
        "C": "11",
        "D": "20"
      },
      "correct_answer": "A"
    },
    {
      "id": 29,
      "difficulty": "medium",
      "question": "📊 Data: 5, 8, 12, 15, 18, 22, 25. Classes: 0-10, 10-20, 20-30. Frequency for 10-20?",
      "options": { "A": 2, "B": 3, "C": 4, "D": 5 },
      "correct_answer": "B"
    },
    {
      "id": 30,
      "difficulty": "medium",
      "question": "📈 If total frequency = 50, and sum of some frequencies = 35, remaining?",
      "options": {
        "A": "15",
        "B": "10",
        "C": "20",
        "D": "25"
      },
      "correct_answer": "A"
    },
    {
      "id": 31,
      "difficulty": "medium",
      "question": "📊 Class boundaries for 10-20 are?",
      "options": {
        "A": "10 and 20",
        "B": "9.5 and 20.5",
        "C": "10.5 and 19.5",
        "D": "9 and 21"
      },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "medium",
      "question": "📋 For class 15.5-25.5, class mark?",
      "options": {
        "A": "20.5",
        "B": "15.5",
        "C": "25.5",
        "D": "21"
      },
      "correct_answer": "A"
    },
    {
      "id": 33,
      "difficulty": "medium",
      "question": "📊 If class size is 5, and lower limit is 12, upper limit?",
      "options": {
        "A": "16",
        "B": "17",
        "C": "15",
        "D": "18"
      },
      "correct_answer": "B"
    },
    {
      "id": 34,
      "difficulty": "medium",
      "question": "📈 A student scores 48. Class 40-50 includes scores?",
      "options": {
        "A": "40 to 49",
        "B": "40 to 50",
        "C": "41 to 50",
        "D": "40.5 to 49.5"
      },
      "correct_answer": "A"
    },
    {
      "id": 35,
      "difficulty": "medium",
      "question": "📊 Frequency table: 0-10:4, 10-20:7, 20-30:9. How many scores ≥10?",
      "options": { "A": 7, "B": 9, "C": 16, "D": 20 },
      "correct_answer": "C"
    },
    {
      "id": 36,
      "difficulty": "medium",
      "question": "📋 For exclusive classes 10-20, 20-30, value 20 belongs to?",
      "options": { "A": "10-20", "B": "20-30", "C": "both", "D": "neither" },
      "correct_answer": "B"
    },
    {
      "id": 37,
      "difficulty": "medium",
      "question": "📊 To make classes continuous, we adjust using?",
      "options": {
        "A": "class marks",
        "B": "class boundaries",
        "C": "frequencies",
        "D": "tallies"
      },
      "correct_answer": "B"
    },
    {
      "id": 38,
      "difficulty": "medium",
      "question": "📈 Class width = 10, lower boundary = 25.5, upper boundary?",
      "options": { "A": "35.5", "B": "34.5", "C": "36.5", "D": "37.5" },
      "correct_answer": "A"
    },
    {
      "id": 39,
      "difficulty": "medium",
      "question": "📊 In a survey, age groups: 0-10, 10-20, etc. This is ___ data.",
      "options": {
        "A": "ungrouped",
        "B": "grouped",
        "C": "raw",
        "D": "sorted"
      },
      "correct_answer": "B"
    },
    {
      "id": 40,
      "difficulty": "medium",
      "question": "📋 If class mark = 30, class size = 10, class interval?",
      "options": {
        "A": "25-35",
        "B": "20-40",
        "C": "26-34",
        "D": "24-36"
      },
      "correct_answer": "A"
    },
    {
      "id": 41,
      "difficulty": "hard",
      "question": "📊 Classes: 0-10, 10-20, 20-30. Frequencies: f1, f2, f3. If total = 100, f1=20, f3=30, f2=?",
      "options": {
        "A": "50",
        "B": "40",
        "C": "45",
        "D": "55"
      },
      "correct_answer": "A"
    },
    {
      "id": 42,
      "difficulty": "hard",
      "question": "📈 Data: 22, 25, 28, 30, 33, 35, 38. Classes: 20-25, 25-30, 30-35, 35-40. Frequency for 30-35?",
      "options": { "A": 1, "B": 2, "C": 3, "D": 4 },
      "correct_answer": "B"
    },
    {
      "id": 43,
      "difficulty": "hard",
      "question": "📊 Class boundaries: 10.5-20.5, 20.5-30.5. Class intervals?",
      "options": {
        "A": "11-20, 21-30",
        "B": "10-20, 20-30",
        "C": "10-21, 20-31",
        "D": "11-21, 21-31"
      },
      "correct_answer": "A"
    },
    {
      "id": 44,
      "difficulty": "hard",
      "question": "📋 For a histogram, we need ___ and ___.",
      "options": {
        "A": "class marks, frequencies",
        "B": "class boundaries, frequencies",
        "C": "class limits, tallies",
        "D": "class size, total"
      },
      "correct_answer": "B"
    },
    {
      "id": 45,
      "difficulty": "hard",
      "question": "📊 If class mark = 42.5, class size = 15, lower limit?",
      "options": {
        "A": "35",
        "B": "32.5",
        "C": "37.5",
        "D": "40"
      },
      "correct_answer": "A"
    },
    {
      "id": 46,
      "difficulty": "hard",
      "question": "📈 Cumulative frequency is used to find?",
      "options": {
        "A": "class marks",
        "B": "number below/above a value",
        "C": "class size",
        "D": "range"
      },
      "correct_answer": "B"
    },
    {
      "id": 47,
      "difficulty": "hard",
      "question": "📊 For classes 0-10, 10-20, etc., if frequency of 10-20 is highest, it's called?",
      "options": {
        "A": "modal class",
        "B": "median class",
        "C": "mean class",
        "D": "range class"
      },
      "correct_answer": "A"
    },
    {
      "id": 48,
      "difficulty": "hard",
      "question": "📋 To find median for grouped data, we need ___ frequency.",
      "options": {
        "A": "cumulative",
        "B": "relative",
        "C": "class",
        "D": "total"
      },
      "correct_answer": "A"
    },
    {
      "id": 49,
      "difficulty": "hard",
      "question": "📊 If class width is 5, and data ranges from 12 to 47, number of classes?",
      "options": {
        "A": "8",
        "B": "7",
        "C": "6",
        "D": "9"
      },
      "correct_answer": "A"
    },
    {
      "id": 50,
      "difficulty": "hard",
      "question": "📈 For grouped data, mean = Σ(f*x) / Σf, where x is?",
      "options": {
        "A": "lower limit",
        "B": "class mark",
        "C": "upper limit",
        "D": "frequency"
      },
      "correct_answer": "B"
    },
    {
      "id": 51,
      "difficulty": "hard",
      "question": "📊 Classes: 20-30, 30-40, 40-50. Frequencies: 5, 12, 8. Total Σf?",
      "options": {
        "A": "25",
        "B": "20",
        "C": "30",
        "D": "35"
      },
      "correct_answer": "A"
    },
    {
      "id": 52,
      "difficulty": "hard",
      "question": "📋 If cumulative frequency up to class 30-40 is 45, and frequency of 30-40 is 15, cumulative before?",
      "options": {
        "A": "30",
        "B": "25",
        "C": "35",
        "D": "40"
      },
      "correct_answer": "A"
    },
    {
      "id": 53,
      "difficulty": "hard",
      "question": "📊 For a dataset, range = 55, class width = 10. Minimum classes needed?",
      "options": {
        "A": "6",
        "B": "5",
        "C": "7",
        "D": "8"
      },
      "correct_answer": "A"
    },
    {
      "id": 54,
      "difficulty": "hard",
      "question": "📈 Class 25-35 has frequency 20. Relative frequency if total=100?",
      "options": { "A": "0.1", "B": "0.2", "C": "0.25", "D": "0.3" },
      "correct_answer": "B"
    },
    {
      "id": 55,
      "difficulty": "hard",
      "question": "📊 To find mode for grouped data, we identify class with ___ frequency.",
      "options": {
        "A": "lowest",
        "B": "highest",
        "C": "cumulative",
        "D": "relative"
      },
      "correct_answer": "B"
    },
    {
      "id": 56,
      "difficulty": "hard",
      "question": "📋 For class 18-22, class mark?",
      "options": {
        "A": "20",
        "B": "18",
        "C": "22",
        "D": "19"
      },
      "correct_answer": "A"
    },
    {
      "id": 57,
      "difficulty": "hard",
      "question": "📊 Data values: 14, 14, 15, 16, 17, 18, 19. Group as 14-16, 17-19. Frequency for 17-19?",
      "options": {
        "A": "3",
        "B": "2",
        "C": "4",
        "D": "5"
      },
      "correct_answer": "A"
    },
    {
      "id": 58,
      "difficulty": "hard",
      "question": "📈 In a frequency polygon, points are plotted at ___ vs frequency.",
      "options": {
        "A": "class limits",
        "B": "class marks",
        "C": "class boundaries",
        "D": "class size"
      },
      "correct_answer": "B"
    },
    {
      "id": 59,
      "difficulty": "hard",
      "question": "📊 If Σf = 80, and median class is 40-50 with cf before = 30, frequency of median class = 20, median position?",
      "options": {
        "A": "40.5th",
        "B": "40th",
        "C": "41st",
        "D": "39th"
      },
      "correct_answer": "A"
    },
    {
      "id": 60,
      "difficulty": "hard",
      "question": "📋 For grouped data, the ___ is an estimate.",
      "options": {
        "A": "mean",
        "B": "range",
        "C": "frequency",
        "D": "class width"
      },
      "correct_answer": "A"
    }
  ]
}