{
  "title": "Volume of Cuboid - Grade 9 CBSE",
  "total_questions": 100,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "What is formula for volume of cuboid?", "options": {"A": "l × b", "B": "l × b × h", "C": "2(lb + bh + hl)", "D": "l + b + h"}, "correct_answer": "B"},
    {"id": 2, "difficulty": "easy", "question": "Find volume of cuboid with l=4 cm, b=3 cm, h=2 cm.", "options": {"A": "9 cm³", "B": "12 cm³", "C": "18 cm³", "D": "24 cm³"}, "correct_answer": "D"},
    {"id": 3, "difficulty": "easy", "question": "Volume of cuboid l=5 m, b=4 m, h=3 m is:", "options": {"A": "12 m³", "B": "30 m³", "C": "48 m³", "D": "60 m³"}, "correct_answer": "D"},
    {"id": 4, "difficulty": "easy", "question": "If l=6 cm, b=5 cm, h=4 cm, volume is:", "options": {"A": "15 cm³", "B": "60 cm³", "C": "120 cm³", "D": "240 cm³"}, "correct_answer": "C"},
    {"id": 5, "difficulty": "easy", "question": "Volume of cuboid with dimensions 2 cm × 3 cm × 4 cm:", "options": {"A": "9 cm³", "B": "14 cm³", "C": "24 cm³", "D": "48 cm³"}, "correct_answer": "C"},
    {"id": 6, "difficulty": "easy", "question": "If volume is 60 cm³, l=5 cm, b=3 cm, find h.", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "C"},
    {"id": 7, "difficulty": "easy", "question": "Cuboid: l=8 m, b=6 m, h=5 m. Volume:", "options": {"A": "120 m³", "B": "180 m³", "C": "240 m³", "D": "320 m³"}, "correct_answer": "C"},
    {"id": 8, "difficulty": "easy", "question": "Volume of cuboid 10 cm × 8 cm × 6 cm:", "options": {"A": "240 cm³", "B": "360 cm³", "C": "480 cm³", "D": "600 cm³"}, "correct_answer": "C"},
    {"id": 9, "difficulty": "easy", "question": "If l=9 cm, b=7 cm, volume=189 cm³, find h.", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "B"},
    {"id": 10, "difficulty": "easy", "question": "Cuboid dimensions 3 m × 2 m × 1 m has volume:", "options": {"A": "3 m³", "B": "6 m³", "C": "9 m³", "D": "12 m³"}, "correct_answer": "B"},
    {"id": 11, "difficulty": "easy", "question": "Volume of cuboid l=12 cm, b=5 cm, h=2 cm:", "options": {"A": "60 cm³", "B": "90 cm³", "C": "120 cm³", "D": "240 cm³"}, "correct_answer": "C"},
    {"id": 12, "difficulty": "easy", "question": "If volume=48 cm³, l=6 cm, h=2 cm, find b.", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "C"},
    {"id": 13, "difficulty": "easy", "question": "Cuboid: l=15 cm, b=10 cm, h=8 cm. Volume:", "options": {"A": "300 cm³", "B": "750 cm³", "C": "1200 cm³", "D": "1500 cm³"}, "correct_answer": "C"},
    {"id": 14, "difficulty": "easy", "question": "Volume of box 20 cm × 15 cm × 10 cm:", "options": {"A": "1500 cm³", "B": "2000 cm³", "C": "2500 cm³", "D": "3000 cm³"}, "correct_answer": "D"},
    {"id": 15, "difficulty": "easy", "question": "If l=14 m, b=7 m, h=3 m, volume:", "options": {"A": "147 m³", "B": "196 m³", "C": "252 m³", "D": "294 m³"}, "correct_answer": "D"},
    {"id": 16, "difficulty": "easy", "question": "Volume=72 cm³, b=6 cm, h=3 cm. Find l.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 17, "difficulty": "easy", "question": "Cuboid dimensions 9 cm × 8 cm × 7 cm volume:", "options": {"A": "216 cm³", "B": "384 cm³", "C": "504 cm³", "D": "648 cm³"}, "correct_answer": "C"},
    {"id": 18, "difficulty": "easy", "question": "If volume=100 cm³, l=10 cm, b=2 cm, h=?", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "C"},
    {"id": 19, "difficulty": "easy", "question": "Cuboid: l=11 cm, b=9 cm, h=4 cm. Volume:", "options": {"A": "198 cm³", "B": "297 cm³", "C": "396 cm³", "D": "495 cm³"}, "correct_answer": "C"},
    {"id": 20, "difficulty": "easy", "question": "Volume of box 25 cm × 20 cm × 4 cm:", "options": {"A": "1000 cm³", "B": "1500 cm³", "C": "2000 cm³", "D": "2500 cm³"}, "correct_answer": "C"},

    {"id": 21, "difficulty": "medium", "question": "Cuboid has l=6.5 cm, b=4.2 cm, h=3.1 cm. Find volume.", "options": {"A": "65.73 cm³", "B": "78.42 cm³", "C": "84.63 cm³", "D": "92.15 cm³"}, "correct_answer": "C"},
    {"id": 22, "difficulty": "medium", "question": "Volume of cuboid is 240 cm³. If l=8 cm, b=5 cm, find h.", "options": {"A": "4 cm", "B": "5 cm", "C": "6 cm", "D": "7 cm"}, "correct_answer": "C"},
    {"id": 23, "difficulty": "medium", "question": "Cuboid dimensions 7.2 m × 5.4 m × 3.6 m. Volume:", "options": {"A": "108.864 m³", "B": "129.6 m³", "C": "139.968 m³", "D": "155.52 m³"}, "correct_answer": "C"},
    {"id": 24, "difficulty": "medium", "question": "If volume=315 cm³, l=9 cm, h=7 cm, find b.", "options": {"A": "4 cm", "B": "5 cm", "C": "6 cm", "D": "7 cm"}, "correct_answer": "B"},
    {"id": 25, "difficulty": "medium", "question": "Cuboid: l=12.5 cm, b=8.4 cm, h=6.2 cm. Volume:", "options": {"A": "525.4 cm³", "B": "589.6 cm³", "C": "651 cm³", "D": "735.8 cm³"}, "correct_answer": "C"},
    {"id": 26, "difficulty": "medium", "question": "Volume=576 cm³, b=9 cm, h=8 cm. Find l.", "options": {"A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "C"},
    {"id": 27, "difficulty": "medium", "question": "Dimensions: 14.3 cm × 10.6 cm × 7.8 cm. Volume:", "options": {"A": "987.324 cm³", "B": "1052.76 cm³", "C": "1178.924 cm³", "D": "1245.38 cm³"}, "correct_answer": "C"},
    {"id": 28, "difficulty": "medium", "question": "If volume=720 cm³, l=15 cm, b=8 cm, h=?", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 29, "difficulty": "medium", "question": "Cuboid: l=16.8 m, b=12.5 m, h=9.2 m. Volume:", "options": {"A": "1456.4 m³", "B": "1687.2 m³", "C": "1932 m³", "D": "2145.6 m³"}, "correct_answer": "C"},
    {"id": 30, "difficulty": "medium", "question": "Volume=882 cm³, l=14 cm, h=7 cm. Find b.", "options": {"A": "7 cm", "B": "8 cm", "C": "9 cm", "D": "10 cm"}, "correct_answer": "C"},
    {"id": 31, "difficulty": "medium", "question": "Dimensions: 18.6 cm × 13.4 cm × 10.8 cm. Volume:", "options": {"A": "2345.832 cm³", "B": "2568.24 cm³", "C": "2691.792 cm³", "D": "2854.368 cm³"}, "correct_answer": "C"},
    {"id": 32, "difficulty": "medium", "question": "If volume=1152 cm³, b=12 cm, h=8 cm, find l.", "options": {"A": "10 cm", "B": "11 cm", "C": "12 cm", "D": "13 cm"}, "correct_answer": "C"},
    {"id": 33, "difficulty": "medium", "question": "Cuboid: l=21.5 cm, b=17.2 cm, h=14.6 cm. Volume:", "options": {"A": "4325.68 cm³", "B": "4892.36 cm³", "C": "5397.08 cm³", "D": "5864.92 cm³"}, "correct_answer": "C"},
    {"id": 34, "difficulty": "medium", "question": "Volume=1512 cm³, l=18 cm, b=12 cm, h=?", "options": {"A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "B"},
    {"id": 35, "difficulty": "medium", "question": "Dimensions: 24.8 m × 19.6 m × 15.4 m. Volume:", "options": {"A": "6254.432 m³", "B": "7128.64 m³", "C": "7486.912 m³", "D": "8254.08 m³"}, "correct_answer": "C"},
    {"id": 36, "difficulty": "medium", "question": "If volume=2016 cm³, l=24 cm, h=14 cm, find b.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 37, "difficulty": "medium", "question": "Cuboid: l=28.4 cm, b=22.7 cm, h=18.9 cm. Volume:", "options": {"A": "10985.652 cm³", "B": "11542.86 cm³", "C": "12187.452 cm³", "D": "12845.28 cm³"}, "correct_answer": "C"},
    {"id": 38, "difficulty": "medium", "question": "Volume=2688 cm³, b=21 cm, h=16 cm. Find l.", "options": {"A": "7 cm", "B": "8 cm", "C": "9 cm", "D": "10 cm"}, "correct_answer": "B"},
    {"id": 39, "difficulty": "medium", "question": "Dimensions: 32.6 cm × 26.8 cm × 22.4 cm. Volume:", "options": {"A": "17845.632 cm³", "B": "18542.88 cm³", "C": "19567.232 cm³", "D": "20458.24 cm³"}, "correct_answer": "C"},
    {"id": 40, "difficulty": "medium", "question": "If volume=3456 cm³, l=36 cm, b=24 cm, h=?", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 41, "difficulty": "medium", "question": "Cuboid: l=3.75 m, b=2.84 m, h=1.96 m. Volume:", "options": {"A": "18.654 m³", "B": "20.874 m³", "C": "22.638 m³", "D": "24.892 m³"}, "correct_answer": "B"},
    {"id": 42, "difficulty": "medium", "question": "Volume=4320 cm³, l=30 cm, h=18 cm. Find b.", "options": {"A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "C"},
    {"id": 43, "difficulty": "medium", "question": "Dimensions: 4.82 cm × 3.76 cm × 2.94 cm. Volume:", "options": {"A": "42.856 cm³", "B": "46.372 cm³", "C": "49.824 cm³", "D": "53.268 cm³"}, "correct_answer": "D"},
    {"id": 44, "difficulty": "medium", "question": "If volume=5184 cm³, b=27 cm, h=24 cm, find l.", "options": {"A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "C"},
    {"id": 45, "difficulty": "medium", "question": "Cuboid: l=5.68 m, b=4.32 m, h=3.76 m. Volume:", "options": {"A": "86.432 m³", "B": "92.176 m³", "C": "96.524 m³", "D": "102.368 m³"}, "correct_answer": "B"},
    {"id": 46, "difficulty": "medium", "question": "Volume=6048 cm³, l=42 cm, b=24 cm, h=?", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 47, "difficulty": "medium", "question": "Dimensions: 6.54 cm × 5.28 cm × 4.62 cm. Volume:", "options": {"A": "145.836 cm³", "B": "152.424 cm³", "C": "159.384 cm³", "D": "165.672 cm³"}, "correct_answer": "C"},
    {"id": 48, "difficulty": "medium", "question": "If volume=7056 cm³, l=49 cm, h=24 cm, find b.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 49, "difficulty": "medium", "question": "Cuboid: l=7.89 m, b=6.45 m, h=5.32 m. Volume:", "options": {"A": "245.678 m³", "B": "258.924 m³", "C": "270.486 m³", "D": "285.632 m³"}, "correct_answer": "C"},
    {"id": 50, "difficulty": "medium", "question": "Volume=8064 cm³, b=32 cm, h=28 cm. Find l.", "options": {"A": "7 cm", "B": "8 cm", "C": "9 cm", "D": "10 cm"}, "correct_answer": "C"},
    {"id": 51, "difficulty": "medium", "question": "Dimensions: 8.76 cm × 7.34 cm × 6.52 cm. Volume:", "options": {"A": "398.652 cm³", "B": "412.836 cm³", "C": "425.648 cm³", "D": "438.924 cm³"}, "correct_answer": "C"},
    {"id": 52, "difficulty": "medium", "question": "If volume=9072 cm³, l=54 cm, b=42 cm, h=?", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 53, "difficulty": "medium", "question": "Cuboid: l=9.87 m, b=8.54 m, h=7.63 m. Volume:", "options": {"A": "642.876 m³", "B": "658.924 m³", "C": "672.458 m³", "D": "685.324 m³"}, "correct_answer": "A"},
    {"id": 54, "difficulty": "medium", "question": "Volume=10080 cm³, l=60 cm, h=42 cm. Find b.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 55, "difficulty": "medium", "question": "Dimensions: 10.98 cm × 9.76 cm × 8.94 cm. Volume:", "options": {"A": "856.432 cm³", "B": "892.764 cm³", "C": "924.568 cm³", "D": "958.672 cm³"}, "correct_answer": "D"},
    {"id": 56, "difficulty": "medium", "question": "If volume=11088 cm³, b=44 cm, h=36 cm, find l.", "options": {"A": "6 cm", "B": "7 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "B"},
    {"id": 57, "difficulty": "medium", "question": "Cuboid: l=12.34 m, b=10.87 m, h=9.65 m. Volume:", "options": {"A": "1294.652 m³", "B": "1328.764 m³", "C": "1356.428 m³", "D": "1382.946 m³"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "medium", "question": "Volume=12096 cm³, l=72 cm, b=42 cm, h=?", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 59, "difficulty": "medium", "question": "Dimensions: 13.56 cm × 12.34 cm × 11.28 cm. Volume:", "options": {"A": "1845.632 cm³", "B": "1892.764 cm³", "C": "1924.856 cm³", "D": "1987.424 cm³"}, "correct_answer": "B"},
    {"id": 60, "difficulty": "medium", "question": "If volume=13104 cm³, l=78 cm, h=42 cm, find b.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 61, "difficulty": "medium", "question": "Cuboid: l=14.78 m, b=13.45 m, h=12.32 m. Volume:", "options": {"A": "2398.652 m³", "B": "2456.432 m³", "C": "2512.764 m³", "D": "2584.928 m³"}, "correct_answer": "B"},
    {"id": 62, "difficulty": "medium", "question": "Volume=14112 cm³, b=56 cm, h=42 cm. Find l.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 63, "difficulty": "medium", "question": "Dimensions: 15.92 cm × 14.68 cm × 13.84 cm. Volume:", "options": {"A": "3234.652 cm³", "B": "3287.424 cm³", "C": "3345.856 cm³", "D": "3428.764 cm³"}, "correct_answer": "A"},
    {"id": 64, "difficulty": "medium", "question": "If volume=15120 cm³, l=90 cm, b=56 cm, h=?", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "B"},
    {"id": 65, "difficulty": "medium", "question": "Cuboid: l=16.54 m, b=15.32 m, h=14.76 m. Volume:", "options": {"A": "3742.856 m³", "B": "3824.432 m³", "C": "3896.528 m³", "D": "3968.764 m³"}, "correct_answer": "B"},
    {"id": 66, "difficulty": "medium", "question": "Volume=16128 cm³, l=96 cm, h=42 cm. Find b.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 67, "difficulty": "medium", "question": "Dimensions: 17.86 cm × 16.74 cm × 15.92 cm. Volume:", "options": {"A": "4762.432 cm³", "B": "4824.856 cm³", "C": "4895.728 cm³", "D": "4968.764 cm³"}, "correct_answer": "A"},
    {"id": 68, "difficulty": "medium", "question": "If volume=17136 cm³, b=68 cm, h=42 cm, find l.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 69, "difficulty": "medium", "question": "Cuboid: l=18.98 m, b=17.86 m, h=16.94 m. Volume:", "options": {"A": "5742.856 m³", "B": "5824.432 m³", "C": "5896.528 m³", "D": "5968.764 m³"}, "correct_answer": "A"},
    {"id": 70, "difficulty": "medium", "question": "Volume=18144 cm³, l=108 cm, b=56 cm, h=?", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "B"},
    {"id": 71, "difficulty": "medium", "question": "Dimensions: 20.12 cm × 19.08 cm × 18.24 cm. Volume:", "options": {"A": "6984.432 cm³", "B": "7056.856 cm³", "C": "7128.764 cm³", "D": "7296.528 cm³"}, "correct_answer": "B"},
    {"id": 72, "difficulty": "medium", "question": "If volume=19152 cm³, l=114 cm, h=42 cm, find b.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 73, "difficulty": "medium", "question": "Cuboid: l=21.34 m, b=20.22 m, h=19.56 m. Volume:", "options": {"A": "8424.856 m³", "B": "8568.432 m³", "C": "8696.528 m³", "D": "8824.764 m³"}, "correct_answer": "A"},
    {"id": 74, "difficulty": "medium", "question": "Volume=20160 cm³, b=70 cm, h=48 cm. Find l.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},
    {"id": 75, "difficulty": "medium", "question": "Dimensions: 22.56 cm × 21.44 cm × 20.68 cm. Volume:", "options": {"A": "9984.432 cm³", "B": "10056.856 cm³", "C": "10128.764 cm³", "D": "10296.528 cm³"}, "correct_answer": "B"},
    {"id": 76, "difficulty": "medium", "question": "If volume=21168 cm³, l=126 cm, b=56 cm, h=?", "options": {"A": "2 cm", "B": "3 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "B"},
    {"id": 77, "difficulty": "medium", "question": "Cuboid: l=23.78 m, b=22.66 m, h=21.94 m. Volume:", "options": {"A": "11824.856 m³", "B": "11968.432 m³", "C": "12096.528 m³", "D": "12248.764 m³"}, "correct_answer": "A"},
    {"id": 78, "difficulty": "medium", "question": "Volume=22176 cm³, l=132 cm, h=42 cm. Find b.", "options": {"A": "3 cm", "B": "4 cm", "C": "5 cm", "D": "6 cm"}, "correct_answer": "B"},
    {"id": 79, "difficulty": "medium", "question": "Dimensions: 24.92 cm × 23.88 cm × 23.12 cm. Volume:", "options": {"A": "13784.432 cm³", "B": "13856.856 cm³", "C": "13928.764 cm³", "D": "14096.528 cm³"}, "correct_answer": "B"},
    {"id": 80, "difficulty": "medium", "question": "If volume=23184 cm³, b=84 cm, h=46 cm, find l.", "options": {"A": "5 cm", "B": "6 cm", "C": "7 cm", "D": "8 cm"}, "correct_answer": "B"},

    {"id": 81, "difficulty": "hard", "question": "Three cuboids of dimensions 6×4×2 cm, 8×6×3 cm, 10×5×4 cm are melted to form single cube. Find side of cube.", "options": {"A": "8 cm", "B": "9 cm", "C": "10 cm", "D": "12 cm"}, "correct_answer": "C"},
    {"id": 82, "difficulty": "hard", "question": "Cuboid has volume 1728 cm³. If ratio of dimensions is 3:4:6, find its dimensions.", "options": {"A": "6,8,12 cm", "B": "9,12,18 cm", "C": "12,16,24 cm", "D": "15,20,30 cm"}, "correct_answer": "A"},
    {"id": 83, "difficulty": "hard", "question": "If surface area of cuboid is 332 cm² and dimensions are in ratio 2:3:5, find its volume.", "options": {"A": "240 cm³", "B": "300 cm³", "C": "360 cm³", "D": "420 cm³"}, "correct_answer": "A"},
    {"id": 84, "difficulty": "hard", "question": "Cuboid has length 15 cm. If breadth is 2/3 of length and height is 4/5 of breadth, find volume.", "options": {"A": "600 cm³", "B": "720 cm³", "C": "800 cm³", "D": "900 cm³"}, "correct_answer": "B"},
    {"id": 85, "difficulty": "hard", "question": "Water in tank 8m×6m×4m is transferred to cubical tank. Find side of cube if 10% water is lost.", "options": {"A": "6 m", "B": "7 m", "C": "8 m", "D": "9 m"}, "correct_answer": "A"},
    {"id": 86, "difficulty": "hard", "question": "Cuboid dimensions increased by 20%, 25%, 30%. Find % increase in volume.", "options": {"A": "75%", "B": "85%", "C": "95%", "D": "105%"}, "correct_answer": "C"},
    {"id": 87, "difficulty": "hard", "question": "If diagonal of cuboid is 14 cm and dimensions are in ratio 1:2:3, find volume.", "options": {"A": "48√14 cm³", "B": "96 cm³", "C": "192 cm³", "D": "384 cm³"}, "correct_answer": "B"},
    {"id": 88, "difficulty": "hard", "question": "Cuboid has volume 3024 cm³. If made of cubes of side 3 cm, how many cubes?", "options": {"A": "96", "B": "108", "C": "112", "D": "124"}, "correct_answer": "C"},
    {"id": 89, "difficulty": "hard", "question": "Three cubes of sides 3cm, 4cm, 5cm melted to form cuboid with square base of side 6cm. Find height.", "options": {"A": "4 cm", "B": "5 cm", "C": "6 cm", "D": "7 cm"}, "correct_answer": "C"},
    {"id": 90, "difficulty": "hard", "question": "Cuboid has total surface area 592 cm². If l:b:h = 5:4:3, find volume.", "options": {"A": "480 cm³", "B": "540 cm³", "C": "600 cm³", "D": "660 cm³"}, "correct_answer": "A"},
    {"id": 91, "difficulty": "hard", "question": "If volume of cuboid is 4032 cm³ and dimensions are consecutive even numbers, find dimensions.", "options": {"A": "12,14,16 cm", "B": "14,16,18 cm", "C": "16,18,20 cm", "D": "18,20,22 cm"}, "correct_answer": "B"},
    {"id": 92, "difficulty": "hard", "question": "Cuboid made of 1 cm cubes has dimensions 12×8×6 cm. If painted on all faces, how many cubes have no paint?", "options": {"A": "240", "B": "320", "C": "384", "D": "400"}, "correct_answer": "A"},
    {"id": 93, "difficulty": "hard", "question": "If length increased by 20%, breadth decreased by 10%, height increased by 30%, find net % change in volume.", "options": {"A": "30.4% increase", "B": "40.4% increase", "C": "50.4% increase", "D": "60.4% increase"}, "correct_answer": "B"},
    {"id": 94, "difficulty": "hard", "question": "Cuboid has diagonal 21 cm. If two dimensions are 12 cm and 9 cm, find volume.", "options": {"A": "432 cm³", "B": "540 cm³", "C": "648 cm³", "D": "756 cm³"}, "correct_answer": "C"},
    {"id": 95, "difficulty": "hard", "question": "Water flows into tank 15m×12m×8m at rate 10 m³/min. How long to fill 3/4 tank?", "options": {"A": "10.8 hrs", "B": "12.6 hrs", "C": "14.4 hrs", "D": "16.2 hrs"}, "correct_answer": "A"},
    {"id": 96, "difficulty": "hard", "question": "Cuboid dimensions in ratio 3:5:7 has volume 840 cm³. Find length of longest diagonal.", "options": {"A": "√83 cm", "B": "√107 cm", "C": "√139 cm", "D": "√163 cm"}, "correct_answer": "D"},
    {"id": 97, "difficulty": "hard", "question": "If cuboid melted to form cylinder of radius 7 cm and height 24 cm, and cuboid had height 8 cm with l:b = 3:2, find dimensions.", "options": {"A": "18,12,8 cm", "B": "21,14,8 cm", "C": "24,16,8 cm", "D": "27,18,8 cm"}, "correct_answer": "B"},
    {"id": 98, "difficulty": "hard", "question": "Cuboid has volume 5760 cm³. If each dimension increased by 2 cm, volume becomes 9000 cm³. Find original dimensions.", "options": {"A": "12,15,16 cm", "B": "15,16,18 cm", "C": "16,18,20 cm", "D": "18,20,24 cm"}, "correct_answer": "C"},
    {"id": 99, "difficulty": "hard", "question": "Three cuboids of dimensions 8×6×4 cm, 12×8×6 cm, 16×10×8 cm melted to form sphere. Find radius of sphere.", "options": {"A": "7 cm", "B": "8 cm", "C": "9 cm", "D": "10 cm"}, "correct_answer": "B"},
    {"id": 100, "difficulty": "hard", "question": "Cuboid has total surface area 1088 cm². If dimensions are in ratio 4:3:2, and it's cut into cubes of side 2 cm, how many cubes?", "options": {"A": "144", "B": "168", "C": "192", "D": "216"}, "correct_answer": "C"}
  ]
}