{
  "title": "Surface Area of Cube, Cuboid, Cylinder - Grade 9 ICSE",
  "total_questions": 60,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "What is the surface area of a cube with side 5 cm? 🧊", "options": {"A": "125 cm²", "B": "150 cm²", "C": "100 cm²", "D": "175 cm²"}, "correct_answer": "B"},
    {"id": 2, "difficulty": "easy", "question": "Formula for total surface area of a cuboid is: 📦", "options": {"A": "l × b", "B": "2(lb + bh + hl)", "C": "l + b + h", "D": "lbh"}, "correct_answer": "B"},
    {"id": 3, "difficulty": "easy", "question": "Find the curved surface area of a cylinder with radius 7 cm and height 10 cm. (π = 22/7) 🥫", "options": {"A": "440 cm²", "B": "220 cm²", "C": "660 cm²", "D": "880 cm²"}, "correct_answer": "A"},
    {"id": 4, "difficulty": "easy", "question": "A cube has side 3 m. Its lateral surface area is? 🔲", "options": {"A": "27 m²", "B": "36 m²", "C": "54 m²", "D": "9 m²"}, "correct_answer": "B"},
    {"id": 5, "difficulty": "easy", "question": "Total surface area of a cylinder = 2πr(h + r). If r=2 cm, h=5 cm, TSA? (π=3.14)", "options": {"A": "87.92 cm²", "B": "62.8 cm²", "C": "75.36 cm²", "D": "100.48 cm²"}, "correct_answer": "A"},
    {"id": 6, "difficulty": "easy", "question": "A cuboid has l=6 cm, b=4 cm, h=3 cm. Its total surface area? 📏", "options": {"A": "72 cm²", "B": "108 cm²", "C": "144 cm²", "D": "180 cm²"}, "correct_answer": "B"},
    {"id": 7, "difficulty": "easy", "question": "Side of a cube doubled, its surface area becomes ___ times. 🔲🔲", "options": {"A": "2", "B": "4", "C": "8", "D": "16"}, "correct_answer": "B"},
    {"id": 8, "difficulty": "easy", "question": "Curved surface area of a cylinder with r=14 cm, h=20 cm (π=22/7) = ?", "options": {"A": "1760 cm²", "B": "880 cm²", "C": "3520 cm²", "D": "2640 cm²"}, "correct_answer": "A"},
    {"id": 9, "difficulty": "easy", "question": "If each edge of cube is 10 cm, find the area of four walls (lateral surface). 🧱", "options": {"A": "600 cm²", "B": "400 cm²", "C": "800 cm²", "D": "200 cm²"}, "correct_answer": "B"},
    {"id": 10, "difficulty": "easy", "question": "A cuboid's length, breadth, height all equal. Then it is a ____.", "options": {"A": "Cube", "B": "Sphere", "C": "Cylinder", "D": "Cone"}, "correct_answer": "A"},
    {"id": 11, "difficulty": "easy", "question": "A closed cylindrical tank radius 1 m, height 2 m. Total surface area? (π=3.14) 🛢️", "options": {"A": "12.56 m²", "B": "18.84 m²", "C": "6.28 m²", "D": "15.7 m²"}, "correct_answer": "B"},
    {"id": 12, "difficulty": "easy", "question": "Lateral surface area of cuboid formula = ?", "options": {"A": "2(lb+bh+hl)", "B": "2h(l+b)", "C": "lbh", "D": "l×b"}, "correct_answer": "B"},
    {"id": 13, "difficulty": "easy", "question": "Surface area of cube = 6a². If a=7 cm, surface area? 📐", "options": {"A": "294 cm²", "B": "343 cm²", "C": "245 cm²", "D": "392 cm²"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "How many faces does a cuboid have? 😀", "options": {"A": "4", "B": "5", "C": "6", "D": "8"}, "correct_answer": "C"},
    {"id": 15, "difficulty": "easy", "question": "A cube's total surface area is 96 cm². Its side length? 🔍", "options": {"A": "8 cm", "B": "6 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "C"},
    {"id": 16, "difficulty": "easy", "question": "A matchbox is an example of a ____. 🧳", "options": {"A": "Cylinder", "B": "Cuboid", "C": "Sphere", "D": "Cone"}, "correct_answer": "B"},
    {"id": 17, "difficulty": "easy", "question": "If radius of cylinder is halved & height doubled, curved surface area ____. 🔄", "options": {"A": "Doubles", "B": "Halves", "C": "Same", "D": "Quadruples"}, "correct_answer": "C"},
    {"id": 18, "difficulty": "easy", "question": "A cube of side 2 cm. Its lateral surface area? 🔳", "options": {"A": "8 cm²", "B": "16 cm²", "C": "24 cm²", "D": "4 cm²"}, "correct_answer": "B"},
    {"id": 19, "difficulty": "easy", "question": "A cuboid l=8 m, b=5 m, h=3 m. Lateral surface area? 🧱", "options": {"A": "79 m²", "B": "158 m²", "C": "78 m²", "D": "120 m²"}, "correct_answer": "C"},
    {"id": 20, "difficulty": "easy", "question": "If TSA of cube is 150 cm², find side length. 📏", "options": {"A": "6 cm", "B": "7 cm", "C": "5 cm", "D": "10 cm"}, "correct_answer": "C"},

    {"id": 21, "difficulty": "medium", "question": "Cuboid dimensions 15 cm × 10 cm × 8 cm. Cost to paint outer surface at ₹0.50/cm²? 💰", "options": {"A": "₹430", "B": "₹215", "C": "₹860", "D": "₹107.5"}, "correct_answer": "B"},
    {"id": 22, "difficulty": "medium", "question": "Curved surface area of cylinder is 660 cm², height 15 cm. Find radius. (π=22/7) 🔍", "options": {"A": "7 cm", "B": "14 cm", "C": "10.5 cm", "D": "3.5 cm"}, "correct_answer": "A"},
    {"id": 23, "difficulty": "medium", "question": "A cube and a sphere have same surface area 154 cm². Find sphere's radius. (π=22/7) ⚖️", "options": {"A": "3.5 cm", "B": "7 cm", "C": "√(154/4π)", "D": "5 cm"}, "correct_answer": "A"},
    {"id": 24, "difficulty": "medium", "question": "A closed cylindrical tank height 1 m, diameter 1.4 m. Area of metal sheet needed? (π=22/7) 🛢️", "options": {"A": "7.48 m²", "B": "5.28 m²", "C": "8.8 m²", "D": "6.16 m²"}, "correct_answer": "D"},
    {"id": 25, "difficulty": "medium", "question": "If lateral surface area of cube is 256 cm², find its volume. 🧊", "options": {"A": "64 cm³", "B": "512 cm³", "C": "256 cm³", "D": "128 cm³"}, "correct_answer": "B"},
    {"id": 26, "difficulty": "medium", "question": "A room 5 m × 4 m × 3 m. Area of 4 walls excluding floor and ceiling? 🏠", "options": {"A": "54 m²", "B": "47 m²", "C": "60 m²", "D": "74 m²"}, "correct_answer": "A"},
    {"id": 27, "difficulty": "medium", "question": "Two cylinders have same curved surface area. Their radii ratio 3:4, heights ratio? 🔄", "options": {"A": "4:3", "B": "3:4", "C": "9:16", "D": "16:9"}, "correct_answer": "A"},
    {"id": 28, "difficulty": "medium", "question": "A cuboid TSA is 332 cm², dimensions 10 cm × 6 cm × x cm. Find x. 📏", "options": {"A": "7 cm", "B": "4 cm", "C": "8 cm", "D": "9 cm"}, "correct_answer": "B"},
    {"id": 29, "difficulty": "medium", "question": "The diameter of a cylinder is 28 cm, height 20 cm. Total surface area? (π=22/7)", "options": {"A": "2992 cm²", "B": "2464 cm²", "C": "3168 cm²", "D": "3872 cm²"}, "correct_answer": "A"},
    {"id": 30, "difficulty": "medium", "question": "A cube's edge increased by 50%. Surface area increases by? 📈", "options": {"A": "50%", "B": "100%", "C": "125%", "D": "150%"}, "correct_answer": "C"},
    {"id": 31, "difficulty": "medium", "question": "If a cuboid's length doubled, breadth halved, height tripled, ratio of new to old TSA? 🔄", "options": {"A": "3:1", "B": "4:3", "C": "8:5", "D": "13:6"}, "correct_answer": "D"},
    {"id": 32, "difficulty": "medium", "question": "A cylinder open at top, radius 7 cm, height 10 cm. Area of metal sheet needed? (π=22/7) 🥫", "options": {"A": "748 cm²", "B": "594 cm²", "C": "1034 cm²", "D": "1232 cm²"}, "correct_answer": "B"},
    {"id": 33, "difficulty": "medium", "question": "A cube of side 8 cm painted on all faces, cut into 1 cm cubes. How many have paint on 2 faces? 🎨", "options": {"A": "48", "B": "72", "C": "64", "D": "96"}, "correct_answer": "B"},
    {"id": 34, "difficulty": "medium", "question": "A rectangular box dimensions 2 m × 1.5 m × 1 m. Cost of painting outer side at ₹2/m²? 💸", "options": {"A": "₹26", "B": "₹34", "C": "₹52", "D": "₹17"}, "correct_answer": "A"},
    {"id": 35, "difficulty": "medium", "question": "Two cubes each side 4 cm joined end to end. Surface area of resulting cuboid? 🔗", "options": {"A": "160 cm²", "B": "192 cm²", "C": "176 cm²", "D": "144 cm²"}, "correct_answer": "A"},
    {"id": 36, "difficulty": "medium", "question": "Cylinder radius r, height h is painted. If r:h = 2:3 and CSA = 132 cm², find r. (π=22/7) 🖌️", "options": {"A": "3.5 cm", "B": "7 cm", "C": "14 cm", "D": "10.5 cm"}, "correct_answer": "B"},
    {"id": 37, "difficulty": "medium", "question": "A cuboid has TSA 94 cm². If length 5 cm, breadth 4 cm, find height. 🔍", "options": {"A": "3 cm", "B": "6 cm", "C": "4 cm", "D": "5 cm"}, "correct_answer": "A"},
    {"id": 38, "difficulty": "medium", "question": "If each edge of cube reduced by 20%, surface area reduces by? 📉", "options": {"A": "20%", "B": "36%", "C": "40%", "D": "64%"}, "correct_answer": "B"},
    {"id": 39, "difficulty": "medium", "question": "A hollow cylinder height 20 cm, inner radius 4 cm, outer radius 5 cm. Total surface area? (π=3.14) 🔁", "options": {"A": "816.4 cm²", "B": "1130.4 cm²", "C": "1256 cm²", "D": "1413 cm²"}, "correct_answer": "B"},
    {"id": 40, "difficulty": "medium", "question": "Cube of side a has same TSA as sphere radius 7 cm. Find a. (π=22/7) ⚖️", "options": {"A": "7 cm", "B": "14 cm", "C": "√(616/6) cm", "D": "√154 cm"}, "correct_answer": "C"},

    {"id": 41, "difficulty": "hard", "question": "A cuboid TSA is 214 cm². Its dimensions are 7 cm, 6 cm and h cm. If h is integer, find possible h. 🔢", "options": {"A": "4 cm", "B": "5 cm", "C": "6 cm", "D": "7 cm"}, "correct_answer": "B"},
    {"id": 42, "difficulty": "hard", "question": "A room 10 m × 8 m × 4 m has a door 2 m × 1 m and two windows 1.5 m × 1 m each. Area of walls to be whitewashed? 🏠", "options": {"A": "256 m²", "B": "254 m²", "C": "250 m²", "D": "248 m²"}, "correct_answer": "D"},
    {"id": 43, "difficulty": "hard", "question": "Two cylinders have volumes equal. Ratio of radii 2:3. Ratio of curved surface areas? 🔄", "options": {"A": "3:2", "B": "4:9", "C": "√3:√2", "D": "9:4"}, "correct_answer": "A"},
    {"id": 44, "difficulty": "hard", "question": "A cube side 10 cm has a cylindrical hole radius 3 cm drilled through center along height. Remaining surface area? (π=3.14) 🕳️", "options": {"A": "600 + 188.4 - 28.26 cm²", "B": "600 - 56.52 + 188.4 cm²", "C": "742.84 cm²", "D": "885.68 cm²"}, "correct_answer": "C"},
    {"id": 45, "difficulty": "hard", "question": "If TSA of cylinder is 2310 cm², radius:height = 2:5. Find radius. (π=22/7) 🔍", "options": {"A": "7 cm", "B": "14 cm", "C": "21 cm", "D": "10.5 cm"}, "correct_answer": "A"},
    {"id": 46, "difficulty": "hard", "question": "From a solid cube of side 14 cm, largest possible sphere carved out. Surface area of remaining solid? (π=22/7) 🧊⚫", "options": {"A": "1176 - 616 + 154 cm²", "B": "1176 cm²", "C": "1680 cm²", "D": "1617 cm²"}, "correct_answer": "C"},
    {"id": 47, "difficulty": "hard", "question": "A cuboid metal sheet 22 cm × 16 cm rolled along length to form cylinder. Curved surface area? 🔄", "options": {"A": "352 cm²", "B": "704 cm²", "C": "176 cm²", "D": "528 cm²"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "hard", "question": "Cylinder radius r, height 2r. Sphere radius r. Ratio of TSA of cylinder to sphere? ⚖️", "options": {"A": "3:2", "B": "4:3", "C": "3:1", "D": "2:1"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "hard", "question": "Three cubes side 3 cm, 4 cm, 5 cm melted to form single cube. TSA of new cube? ♻️", "options": {"A": "216 cm²", "B": "384 cm²", "C": "486 cm²", "D": "600 cm²"}, "correct_answer": "A"},
    {"id": 50, "difficulty": "hard", "question": "A cylinder CSA is 4400 cm², height 25 cm. It's cut into two cylinders along height. Total new surface area increase? ✂️", "options": {"A": "4400 cm²", "B": "8800 cm²", "C": "0 cm²", "D": "2200 cm²"}, "correct_answer": "B"},
    {"id": 51, "difficulty": "hard", "question": "Water flows through cylindrical pipe radius 7 cm, length 5 km. Inner curved surface area in m²? (π=22/7) 🌊", "options": {"A": "2200 m²", "B": "4400 m²", "C": "1100 m²", "D": "3300 m²"}, "correct_answer": "A"},
    {"id": 52, "difficulty": "hard", "question": "Cube TSA increased by 69%. Edge increased by? 📈", "options": {"A": "20%", "B": "25%", "C": "30%", "D": "40%"}, "correct_answer": "C"},
    {"id": 53, "difficulty": "hard", "question": "A cuboid 12×9×8 cm painted and cut into 1 cm cubes. Cubes with no face painted? 🎨", "options": {"A": "360", "B": "384", "C": "420", "D": "504"}, "correct_answer": "D"},
    {"id": 54, "difficulty": "hard", "question": "A cylindrical pillar radius 28 cm, height 4 m to be painted at ₹0.50/m². Cost? (π=22/7) 💰", "options": {"A": "₹17.60", "B": "₹35.20", "C": "₹70.40", "D": "₹8.80"}, "correct_answer": "B"},
    {"id": 55, "difficulty": "hard", "question": "Ratio of TSA of cube to sphere is 1:1. If sphere radius 7 cm, cube side? (π=22/7) ⚖️", "options": {"A": "√(616/6) cm", "B": "14 cm", "C": "7 cm", "D": "28/√π cm"}, "correct_answer": "A"},
    {"id": 56, "difficulty": "hard", "question": "A rectangular tank open at top: l=2.5 m, b=2 m, h=1.5 m. Cost of lining inside with tin at ₹10/m²? 🛢️", "options": {"A": "₹365", "B": "₹285", "C": "₹235", "D": "₹185"}, "correct_answer": "C"},
    {"id": 57, "difficulty": "hard", "question": "Two cylinders A & B have heights 10 cm, 20 cm, radii 7 cm, 3.5 cm respectively. Ratio of their TSA? 🔄", "options": {"A": "2:1", "B": "4:1", "C": "3:2", "D": "5:3"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "hard", "question": "A cube of side 12 cm has square holes of side 4 cm drilled through each face center. Remaining surface area? 🕳️", "options": {"A": "864 - 288 + 768 cm²", "B": "1344 cm²", "C": "960 cm²", "D": "1152 cm²"}, "correct_answer": "B"},
    {"id": 59, "difficulty": "hard", "question": "Cylinder height = diameter. If TSA is 462 cm², find radius. (π=22/7) 🔄", "options": {"A": "3.5 cm", "B": "7 cm", "C": "14 cm", "D": "21 cm"}, "correct_answer": "A"},
    {"id": 60, "difficulty": "hard", "question": "A cuboid is cut into two cubes of equal volume. Original cuboid TSA 360 cm². Each cube's TSA? ✂️", "options": {"A": "180 cm²", "B": "216 cm²", "C": "240 cm²", "D": "270 cm²"}, "correct_answer": "B"}
  ]
}