{
  "title": "Mode (Statistics) - Grade 10 CBSE",
  "total_questions": 100,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "Mode is the value that appears:", "options": {"A": "Most frequently", "B": "In the middle", "C": "First", "D": "Last"}, "correct_answer": "A"},
    {"id": 2, "difficulty": "easy", "question": "For ungrouped data: 2,3,2,4,2,5, mode is:", "options": {"A": "2", "B": "3", "C": "4", "D": "5"}, "correct_answer": "A"},
    {"id": 3, "difficulty": "easy", "question": "A distribution can have:", "options": {"A": "One or more modes", "B": "Only one mode", "C": "Exactly three modes", "D": "No mode"}, "correct_answer": "A"},
    {"id": 4, "difficulty": "easy", "question": "For data: 1,2,3,4,5, mode is:", "options": {"A": "No mode", "B": "3", "C": "2.5", "D": "All values"}, "correct_answer": "A"},
    {"id": 5, "difficulty": "easy", "question": "For grouped data, modal class is class with:", "options": {"A": "Highest frequency", "B": "Lowest frequency", "C": "Middle frequency", "D": "Cumulative frequency N/2"}, "correct_answer": "A"},
    {"id": 6, "difficulty": "easy", "question": "In mode formula, l represents:", "options": {"A": "Lower limit of modal class", "B": "Upper limit of modal class", "C": "Class width", "D": "Frequency"}, "correct_answer": "A"},
    {"id": 7, "difficulty": "easy", "question": "In mode formula, f1 represents:", "options": {"A": "Frequency of modal class", "B": "Frequency before modal class", "C": "Frequency after modal class", "D": "Total frequency"}, "correct_answer": "A"},
    {"id": 8, "difficulty": "easy", "question": "In mode formula, f0 represents:", "options": {"A": "Frequency before modal class", "B": "Frequency of modal class", "C": "Frequency after modal class", "D": "Cumulative frequency"}, "correct_answer": "A"},
    {"id": 9, "difficulty": "easy", "question": "In mode formula, f2 represents:", "options": {"A": "Frequency after modal class", "B": "Frequency before modal class", "C": "Frequency of modal class", "D": "Total frequency"}, "correct_answer": "A"},
    {"id": 10, "difficulty": "easy", "question": "In mode formula, h represents:", "options": {"A": "Class width of modal class", "B": "Height", "C": "Hypotenuse", "D": "Highest value"}, "correct_answer": "A"},
    {"id": 11, "difficulty": "easy", "question": "For data: 5,7,5,8,5,9, mode is:", "options": {"A": "5", "B": "7", "C": "8", "D": "9"}, "correct_answer": "A"},
    {"id": 12, "difficulty": "easy", "question": "If two values appear equally often, distribution is:", "options": {"A": "Bimodal", "B": "Unimodal", "C": "Trimodal", "D": "No mode"}, "correct_answer": "A"},
    {"id": 13, "difficulty": "easy", "question": "For data: 3,3,4,4,5,5, mode is:", "options": {"A": "3,4,5", "B": "4", "C": "No mode", "D": "3.5"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "Mode can be found from:", "options": {"A": "Histogram", "B": "Ogive", "C": "Frequency polygon", "D": "Pie chart"}, "correct_answer": "A"},
    {"id": 15, "difficulty": "easy", "question": "For classes: 0-10:5, 10-20:8, 20-30:12, modal class is:", "options": {"A": "20-30", "B": "10-20", "C": "0-10", "D": "None"}, "correct_answer": "A"},
    {"id": 16, "difficulty": "easy", "question": "Mode is a measure of:", "options": {"A": "Central tendency", "B": "Dispersion", "C": "Correlation", "D": "Regression"}, "correct_answer": "A"},
    {"id": 17, "difficulty": "easy", "question": "For categorical data, best measure is:", "options": {"A": "Mode", "B": "Mean", "C": "Median", "D": "Range"}, "correct_answer": "A"},
    {"id": 18, "difficulty": "easy", "question": "If all frequencies are equal, mode is:", "options": {"A": "Not defined", "B": "First value", "C": "Last value", "D": "All values"}, "correct_answer": "A"},
    {"id": 19, "difficulty": "easy", "question": "For data: 10,10,10,10, mode is:", "options": {"A": "10", "B": "No mode", "C": "40", "D": "0"}, "correct_answer": "A"},
    {"id": 20, "difficulty": "easy", "question": "Mode formula for grouped data is:", "options": {"A": "l + [(f1-f0)/(2f1-f0-f2)] × h", "B": "l + [(f1-f0)/(f1-f0-f2)] × h", "C": "l + [(2f1-f0-f2)/(f1-f0)] × h", "D": "l + h/2"}, "correct_answer": "A"},
    
    {"id": 21, "difficulty": "medium", "question": "Classes: 0-10:5, 10-20:12, 20-30:8, 30-40:5. Modal class:", "options": {"A": "10-20", "B": "20-30", "C": "0-10", "D": "30-40"}, "correct_answer": "A"},
    {"id": 22, "difficulty": "medium", "question": "Given: l=20, f1=15, f0=10, f2=8, h=10. Mode =", "options": {"A": "24.17", "B": "22.5", "C": "25", "D": "23.33"}, "correct_answer": "A"},
    {"id": 23, "difficulty": "medium", "question": "Classes: 10-20:4, 20-30:9, 30-40:6, 40-50:3. Mode =", "options": {"A": "25.71", "B": "24.29", "C": "26.43", "D": "23.57"}, "correct_answer": "A"},
    {"id": 24, "difficulty": "medium", "question": "Data: 5,8,5,9,5,7,8,8. Mode:", "options": {"A": "5 and 8", "B": "5", "C": "8", "D": "7"}, "correct_answer": "A"},
    {"id": 25, "difficulty": "medium", "question": "Classes: 0-20:10, 20-40:15, 40-60:20, 60-80:15. Modal class:", "options": {"A": "40-60", "B": "20-40", "C": "60-80", "D": "0-20"}, "correct_answer": "A"},
    {"id": 26, "difficulty": "medium", "question": "If l=30, f1=25, f0=15, f2=20, h=10, mode =", "options": {"A": "33.33", "B": "32", "C": "34.67", "D": "31.5"}, "correct_answer": "A"},
    {"id": 27, "difficulty": "medium", "question": "Classes: 0-10:8, 10-20:12, 20-30:15, 30-40:10. Mode =", "options": {"A": "23.64", "B": "22.86", "C": "24.29", "D": "21.43"}, "correct_answer": "A"},
    {"id": 28, "difficulty": "medium", "question": "Data: 12,15,12,18,15,20,15,12. Mode:", "options": {"A": "12 and 15", "B": "12", "C": "15", "D": "18"}, "correct_answer": "A"},
    {"id": 29, "difficulty": "medium", "question": "Classes: 20-30:5, 30-40:8, 40-50:12, 50-60:8. l for modal class =", "options": {"A": "40", "B": "30", "C": "50", "D": "20"}, "correct_answer": "A"},
    {"id": 30, "difficulty": "medium", "question": "If f1=20, f0=12, f2=15, l=25, h=5, mode =", "options": {"A": "27.31", "B": "26.92", "C": "28.08", "D": "25.77"}, "correct_answer": "A"},
    {"id": 31, "difficulty": "medium", "question": "Classes: 0-5:3, 5-10:7, 10-15:10, 15-20:5. Modal class:", "options": {"A": "10-15", "B": "5-10", "C": "15-20", "D": "0-5"}, "correct_answer": "A"},
    {"id": 32, "difficulty": "medium", "question": "Data: 3,5,3,7,5,9,7,3,5. Mode:", "options": {"A": "3", "B": "5", "C": "3 and 5", "D": "7"}, "correct_answer": "A"},
    {"id": 33, "difficulty": "medium", "question": "Classes: 100-200:4, 200-300:9, 300-400:6, 400-500:3. Mode =", "options": {"A": "257.14", "B": "242.86", "C": "271.43", "D": "228.57"}, "correct_answer": "A"},
    {"id": 34, "difficulty": "medium", "question": "If modal class is 30-40, then l=", "options": {"A": "30", "B": "40", "C": "35", "D": "10"}, "correct_answer": "A"},
    {"id": 35, "difficulty": "medium", "question": "Classes: 0-10:5, 10-20:10, 20-30:15, 30-40:10, 40-50:5. Mode =", "options": {"A": "25", "B": "24", "C": "26", "D": "23"}, "correct_answer": "A"},
    {"id": 36, "difficulty": "medium", "question": "Data: 22,25,22,28,25,30,28,22. Mode:", "options": {"A": "22", "B": "25", "C": "28", "D": "22 and 25"}, "correct_answer": "A"},
    {"id": 37, "difficulty": "medium", "question": "Classes: 10-15:4, 15-20:7, 20-25:10, 25-30:6. l for modal class =", "options": {"A": "20", "B": "15", "C": "25", "D": "10"}, "correct_answer": "A"},
    {"id": 38, "difficulty": "medium", "question": "If l=40, f1=18, f0=12, f2=10, h=10, mode =", "options": {"A": "45", "B": "43.75", "C": "46.25", "D": "42.5"}, "correct_answer": "A"},
    {"id": 39, "difficulty": "medium", "question": "Classes: 0-20:8, 20-40:12, 40-60:18, 60-80:12. Modal class:", "options": {"A": "40-60", "B": "20-40", "C": "60-80", "D": "0-20"}, "correct_answer": "A"},
    {"id": 40, "difficulty": "medium", "question": "Data: 7,9,7,11,9,13,11,7,9,11. Mode:", "options": {"A": "7 and 9", "B": "7", "C": "9", "D": "11"}, "correct_answer": "A"},
    {"id": 41, "difficulty": "medium", "question": "Classes: 0-50:5, 50-100:10, 100-150:15, 150-200:10. Mode =", "options": {"A": "116.67", "B": "120", "C": "113.33", "D": "125"}, "correct_answer": "A"},
    {"id": 42, "difficulty": "medium", "question": "If modal class frequency is 25, before class frequency is 15, after class frequency is 20, then f1-f0 =", "options": {"A": "10", "B": "5", "C": "15", "D": "25"}, "correct_answer": "A"},
    {"id": 43, "difficulty": "medium", "question": "Classes: 20-25:3, 25-30:6, 30-35:9, 35-40:6. Mode =", "options": {"A": "32.5", "B": "31.25", "C": "33.75", "D": "30"}, "correct_answer": "A"},
    {"id": 44, "difficulty": "medium", "question": "Data: 15,18,15,20,18,22,20,15. Mode:", "options": {"A": "15", "B": "18", "C": "20", "D": "15 and 18"}, "correct_answer": "A"},
    {"id": 45, "difficulty": "medium", "question": "Classes: 0-10:6, 10-20:9, 20-30:12, 30-40:9. 2f1-f0-f2 =", "options": {"A": "6", "B": "12", "C": "9", "D": "3"}, "correct_answer": "A"},
    {"id": 46, "difficulty": "medium", "question": "If l=100, f1=30, f0=20, f2=25, h=50, mode =", "options": {"A": "133.33", "B": "125", "C": "141.67", "D": "116.67"}, "correct_answer": "A"},
    {"id": 47, "difficulty": "medium", "question": "Classes: 5-10:4, 10-15:8, 15-20:12, 20-25:8. Modal class:", "options": {"A": "15-20", "B": "10-15", "C": "20-25", "D": "5-10"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "medium", "question": "Data: 25,28,25,30,28,32,30,25,28. Mode:", "options": {"A": "25 and 28", "B": "25", "C": "28", "D": "30"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "medium", "question": "Classes: 0-25:5, 25-50:10, 50-75:15, 75-100:10. Mode =", "options": {"A": "62.5", "B": "60", "C": "65", "D": "57.5"}, "correct_answer": "A"},
    {"id": 50, "difficulty": "medium", "question": "If f1-f0=8, 2f1-f0-f2=16, l=30, h=10, mode =", "options": {"A": "35", "B": "33", "C": "37", "D": "32"}, "correct_answer": "A"},
    {"id": 51, "difficulty": "medium", "question": "Classes: 30-40:5, 40-50:8, 50-60:12, 60-70:8. l for modal class =", "options": {"A": "50", "B": "40", "C": "60", "D": "30"}, "correct_answer": "A"},
    {"id": 52, "difficulty": "medium", "question": "Data: 8,10,8,12,10,14,12,8,10,12. Mode:", "options": {"A": "8 and 10", "B": "8", "C": "10", "D": "12"}, "correct_answer": "A"},
    {"id": 53, "difficulty": "medium", "question": "Classes: 0-100:3, 100-200:7, 200-300:10, 300-400:7. Mode =", "options": {"A": "250", "B": "240", "C": "260", "D": "230"}, "correct_answer": "A"},
    {"id": 54, "difficulty": "medium", "question": "If modal class is 40-50 with h=10, then class width =", "options": {"A": "10", "B": "40", "C": "50", "D": "90"}, "correct_answer": "A"},
    {"id": 55, "difficulty": "medium", "question": "Classes: 0-20:8, 20-40:12, 40-60:16, 60-80:12. Mode =", "options": {"A": "46.67", "B": "45", "C": "48.33", "D": "43.33"}, "correct_answer": "A"},
    {"id": 56, "difficulty": "medium", "question": "Data: 18,20,18,22,20,24,22,18,20,22. Mode:", "options": {"A": "18 and 20", "B": "18", "C": "20", "D": "22"}, "correct_answer": "A"},
    {"id": 57, "difficulty": "medium", "question": "Classes: 10-20:4, 20-30:7, 30-40:11, 40-50:7. f0 for modal class =", "options": {"A": "7", "B": "4", "C": "11", "D": "7"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "medium", "question": "If l=35, f1=24, f0=18, f2=20, h=5, mode =", "options": {"A": "37", "B": "36.33", "C": "37.67", "D": "35.83"}, "correct_answer": "A"},
    {"id": 59, "difficulty": "medium", "question": "Classes: 0-5:3, 5-10:6, 10-15:9, 15-20:6. Modal class:", "options": {"A": "10-15", "B": "5-10", "C": "15-20", "D": "0-5"}, "correct_answer": "A"},
    {"id": 60, "difficulty": "medium", "question": "Data: 30,33,30,36,33,39,36,30. Mode:", "options": {"A": "30", "B": "33", "C": "36", "D": "30 and 33"}, "correct_answer": "A"},
    {"id": 61, "difficulty": "medium", "question": "Classes: 20-30:5, 30-40:10, 40-50:15, 50-60:10. f2 for modal class =", "options": {"A": "10", "B": "5", "C": "15", "D": "25"}, "correct_answer": "A"},
    {"id": 62, "difficulty": "medium", "question": "If mode=45, l=40, f1-f0=10, 2f1-f0-f2=20, h=10, check consistency.", "options": {"A": "Consistent", "B": "Inconsistent", "C": "Cannot determine", "D": "Partially consistent"}, "correct_answer": "A"},
    {"id": 63, "difficulty": "medium", "question": "Classes: 0-10:7, 10-20:12, 20-30:18, 30-40:13. Mode =", "options": {"A": "24", "B": "23.33", "C": "24.67", "D": "22.5"}, "correct_answer": "A"},
    {"id": 64, "difficulty": "medium", "question": "Data: 12,14,12,16,14,18,16,12,14. Mode:", "options": {"A": "12 and 14", "B": "12", "C": "14", "D": "16"}, "correct_answer": "A"},
    {"id": 65, "difficulty": "medium", "question": "Classes: 40-50:4, 50-60:8, 60-70:12, 70-80:8. l for modal class =", "options": {"A": "60", "B": "50", "C": "70", "D": "40"}, "correct_answer": "A"},
    {"id": 66, "difficulty": "medium", "question": "If f1=28, f0=20, f2=24, l=30, h=5, mode =", "options": {"A": "31.67", "B": "30.83", "C": "32.5", "D": "29.17"}, "correct_answer": "A"},
    {"id": 67, "difficulty": "medium", "question": "Classes: 0-25:6, 25-50:10, 50-75:14, 75-100:10. Modal class:", "options": {"A": "50-75", "B": "25-50", "C": "75-100", "D": "0-25"}, "correct_answer": "A"},
    {"id": 68, "difficulty": "medium", "question": "Data: 22,24,22,26,24,28,26,22,24,26. Mode:", "options": {"A": "22 and 24", "B": "22", "C": "24", "D": "26"}, "correct_answer": "A"},
    {"id": 69, "difficulty": "medium", "question": "Classes: 100-150:5, 150-200:9, 200-250:13, 250-300:9. Mode =", "options": {"A": "225", "B": "220", "C": "230", "D": "215"}, "correct_answer": "A"},
    {"id": 70, "difficulty": "medium", "question": "If modal class is 30-40, f1=25, f0=18, f2=20, mode =", "options": {"A": "34.17", "B": "33.33", "C": "35", "D": "32.5"}, "correct_answer": "A"},
    {"id": 71, "difficulty": "medium", "question": "Classes: 0-15:4, 15-30:8, 30-45:12, 45-60:8. f1-f0 for modal class =", "options": {"A": "4", "B": "8", "C": "12", "D": "20"}, "correct_answer": "A"},
    {"id": 72, "difficulty": "medium", "question": "Data: 35,38,35,40,38,42,40,35. Mode:", "options": {"A": "35", "B": "38", "C": "40", "D": "35 and 38"}, "correct_answer": "A"},
    {"id": 73, "difficulty": "medium", "question": "Classes: 5-15:5, 15-25:9, 25-35:13, 35-45:9. 2f1-f0-f2 =", "options": {"A": "8", "B": "13", "C": "9", "D": "22"}, "correct_answer": "A"},
    {"id": 74, "difficulty": "medium", "question": "If l=45, mode=48, f1-f0=6, h=10, find 2f1-f0-f2.", "options": {"A": "20", "B": "15", "C": "18", "D": "12"}, "correct_answer": "A"},
    {"id": 75, "difficulty": "medium", "question": "Classes: 0-20:10, 20-40:15, 40-60:20, 60-80:15. Mode =", "options": {"A": "46.67", "B": "45", "C": "48.33", "D": "43.33"}, "correct_answer": "A"},
    {"id": 76, "difficulty": "medium", "question": "Data: 28,30,28,32,30,34,32,28,30. Mode:", "options": {"A": "28 and 30", "B": "28", "C": "30", "D": "32"}, "correct_answer": "A"},
    {"id": 77, "difficulty": "medium", "question": "Classes: 30-35:4, 35-40:7, 40-45:10, 45-50:7. l for modal class =", "options": {"A": "40", "B": "35", "C": "45", "D": "30"}, "correct_answer": "A"},
    {"id": 78, "difficulty": "medium", "question": "If mode=52.5, l=50, h=10, f1-f0=5, find 2f1-f0-f2.", "options": {"A": "20", "B": "15", "C": "25", "D": "10"}, "correct_answer": "A"},
    {"id": 79, "difficulty": "medium", "question": "Classes: 0-10:8, 10-20:14, 20-30:20, 30-40:14. Mode =", "options": {"A": "23.33", "B": "22.5", "C": "24.17", "D": "21.67"}, "correct_answer": "A"},
    {"id": 80, "difficulty": "medium", "question": "Data: 42,45,42,48,45,50,48,42. Mode:", "options": {"A": "42", "B": "45", "C": "48", "D": "42 and 45"}, "correct_answer": "A"},
    
    {"id": 81, "difficulty": "hard", "question": "Classes: 0-10:5, 10-20:8, 20-30:12, 30-40:15, 40-50:10. If mode=34, find f1 for modal class 30-40.", "options": {"A": "15", "B": "12", "C": "10", "D": "8"}, "correct_answer": "A"},
    {"id": 82, "difficulty": "hard", "question": "For data with mode=25, if each value increased by 5, new mode:", "options": {"A": "30", "B": "25", "C": "20", "D": "35"}, "correct_answer": "A"},
    {"id": 83, "difficulty": "hard", "question": "Classes: 0-20:10, 20-40:15, 40-60:f, 60-80:10. If mode=50 and f is modal class frequency, find f assuming f0=15, f2=10.", "options": {"A": "25", "B": "20", "C": "30", "D": "35"}, "correct_answer": "A"},
    {"id": 84, "difficulty": "hard", "question": "If mode of 10 numbers is 15 and each number multiplied by 3, new mode:", "options": {"A": "45", "B": "15", "C": "5", "D": "30"}, "correct_answer": "A"},
    {"id": 85, "difficulty": "hard", "question": "Classes: 10-20:4, 20-30:6, 30-40:10, 40-50:8. If frequencies in first two classes doubled, new mode (original mode=36):", "options": {"A": "36", "B": "35.5", "C": "36.5", "D": "35"}, "correct_answer": "A"},
    {"id": 86, "difficulty": "hard", "question": "For grouped data, if class intervals changed but frequencies remain proportional, mode:", "options": {"A": "Changes slightly", "B": "Remains same", "C": "Doubles", "D": "Halves"}, "correct_answer": "A"},
    {"id": 87, "difficulty": "hard", "question": "Classes: 0-100:2, 100-200:5, 200-300:8, 300-400:5. If all class marks increased by 50, new mode:", "options": {"A": "Increases by 50", "B": "Remains same", "C": "Decreases by 50", "D": "Doubles"}, "correct_answer": "A"},
    {"id": 88, "difficulty": "hard", "question": "If in modal class f1=20, and f1-f0=6, 2f1-f0-f2=12, find f0 and f2.", "options": {"A": "f0=14, f2=16", "B": "f0=16, f2=14", "C": "f0=12, f2=18", "D": "f0=18, f2=12"}, "correct_answer": "A"},
    {"id": 89, "difficulty": "hard", "question": "Classes: 0-10:a, 10-20:10, 20-30:15, 30-40:10. If modal class is 20-30 and mode=25, find a.", "options": {"A": "5", "B": "8", "C": "10", "D": "12"}, "correct_answer": "A"},
    {"id": 90, "difficulty": "hard", "question": "For data: x, 2x, x, 3x, 2x, 4x, 3x. Mode:", "options": {"A": "x", "B": "2x", "C": "3x", "D": "x and 2x"}, "correct_answer": "A"},
    {"id": 91, "difficulty": "hard", "question": "Classes: 20-30:5, 30-40:8, 40-50:12, 50-60:8. If each frequency increased by 3, new mode:", "options": {"A": "Same as original", "B": "Increases", "C": "Decreases", "D": "Cannot determine"}, "correct_answer": "A"},
    {"id": 92, "difficulty": "hard", "question": "If mode formula gives value outside modal class, it means:", "options": {"A": "Calculation error", "B": "Valid result", "C": "Data is symmetric", "D": "Mode is at boundary"}, "correct_answer": "A"},
    {"id": 93, "difficulty": "hard", "question": "Classes: 0-20:10, 20-40:15, 40-60:25, 60-80:10. If class intervals changed to 0-10,10-20,...,70-80, new mode:", "options": {"A": "Approximately same", "B": "Doubles", "C": "Halves", "D": "Increases by 10"}, "correct_answer": "A"},
    {"id": 94, "difficulty": "hard", "question": "For data with mode 40, if each value decreased by 25%, new mode:", "options": {"A": "30", "B": "40", "C": "50", "D": "35"}, "correct_answer": "A"},
    {"id": 95, "difficulty": "hard", "question": "Classes: 0-10:4, 10-20:6, 20-30:10, 30-40:x. If mode=27.5 and x is frequency of modal class, find x.", "options": {"A": "12", "B": "10", "C": "8", "D": "15"}, "correct_answer": "A"},
    {"id": 96, "difficulty": "hard", "question": "If for three numbers a,b,c with a<b<c, mode is b, which is true?", "options": {"A": "b appears most", "B": "a appears most", "C": "c appears most", "D": "All equal"}, "correct_answer": "A"},
    {"id": 97, "difficulty": "hard", "question": "Classes: 100-120:5, 120-140:8, 140-160:12, 160-180:5. If all class widths doubled, new mode:", "options": {"A": "Doubles", "B": "Same", "C": "Halves", "D": "Increases by 20"}, "correct_answer": "A"},
    {"id": 98, "difficulty": "hard", "question": "For symmetric unimodal distribution, mode equals:", "options": {"A": "Mean and median", "B": "Mean only", "C": "Median only", "D": "Neither"}, "correct_answer": "A"},
    {"id": 99, "difficulty": "hard", "question": "Classes: 0-5:2, 5-10:4, 10-15:6, 15-20:3. If frequencies in classes 10-15 and 15-20 swapped, new mode:", "options": {"A": "Changes", "B": "Same", "C": "Becomes 7.5", "D": "Cannot determine"}, "correct_answer": "A"},
    {"id": 100, "difficulty": "hard", "question": "If mode of a,b,c,d is b, and a=10, c=30, d=40, possible value of b if data is 10,b,30,40,b,30:", "options": {"A": "30", "B": "10", "C": "40", "D": "20"}, "correct_answer": "A"}
  ]
}