{
  "title": "Surface Area and Volume of Solids - Grade 10 ICSE",
  "total_questions": 60,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "Cube side 4cm. Volume? 🧊", "options": {"A": "64 cm³", "B": "16 cm³", "C": "96 cm³", "D": "48 cm³"}, "correct_answer": "A"},
    {"id": 2, "difficulty": "easy", "question": "Cuboid 3cm×4cm×5cm. Surface area? 📦", "options": {"A": "94 cm²", "B": "60 cm²", "C": "47 cm²", "D": "120 cm²"}, "correct_answer": "A"},
    {"id": 3, "difficulty": "easy", "question": "Cylinder radius 7cm, height 10cm. Volume? 🛢️", "options": {"A": "1540 cm³", "B": "440 cm²", "C": "154 cm²", "D": "3080 cm³"}, "correct_answer": "A"},
    {"id": 4, "difficulty": "easy", "question": "Sphere radius 3cm. Surface area? ⚫", "options": {"A": "36π cm²", "B": "12π cm²", "C": "18π cm²", "D": "27π cm²"}, "correct_answer": "A"},
    {"id": 5, "difficulty": "easy", "question": "Cone radius 6cm, height 8cm. Volume? 🔺", "options": {"A": "96π cm³", "B": "48π cm³", "C": "144π cm³", "D": "64π cm³"}, "correct_answer": "A"},
    {"id": 6, "difficulty": "easy", "question": "Cube side 5cm. Total surface area? ✅", "options": {"A": "150 cm²", "B": "125 cm³", "C": "100 cm²", "D": "75 cm²"}, "correct_answer": "A"},
    {"id": 7, "difficulty": "easy", "question": "Cylinder curved surface area formula? 📐", "options": {"A": "2πrh", "B": "πr²h", "C": "πr²", "D": "2πr²"}, "correct_answer": "A"},
    {"id": 8, "difficulty": "easy", "question": "Hemisphere radius 7cm. Volume? 🌓", "options": {"A": "(686/3)π cm³", "B": "343π cm³", "C": "1372π cm³", "D": "98π cm³"}, "correct_answer": "A"},
    {"id": 9, "difficulty": "easy", "question": "Cuboid volume formula? 📏", "options": {"A": "l×b×h", "B": "2(lb+bh+hl)", "C": "l+b+h", "D": "lb+bh"}, "correct_answer": "A"},
    {"id": 10, "difficulty": "easy", "question": "Cone curved surface area formula? 🍦", "options": {"A": "πrl", "B": "πr²h/3", "C": "πr²", "D": "2πr"}, "correct_answer": "A"},
    {"id": 11, "difficulty": "easy", "question": "Sphere volume formula? 🎾", "options": {"A": "(4/3)πr³", "B": "4πr²", "C": "πr³", "D": "(2/3)πr³"}, "correct_answer": "A"},
    {"id": 12, "difficulty": "easy", "question": "Cube diagonal formula? 🔷", "options": {"A": "√3 × side", "B": "√2 × side", "C": "3 × side", "D": "side/√2"}, "correct_answer": "A"},
    {"id": 13, "difficulty": "easy", "question": "Cylinder total surface area? 🛢️", "options": {"A": "2πr(h+r)", "B": "2πrh", "C": "πr²h", "D": "πr²"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "Hemisphere curved surface area? 🌓", "options": {"A": "2πr²", "B": "3πr²", "C": "πr²", "D": "4πr²"}, "correct_answer": "A"},
    {"id": 15, "difficulty": "easy", "question": "Cone total surface area? 📊", "options": {"A": "πr(l+r)", "B": "πrl", "C": "πr²", "D": "πr²h/3"}, "correct_answer": "A"},
    {"id": 16, "difficulty": "easy", "question": "If cube side doubles, volume becomes ___ times. ⬆️", "options": {"A": "8", "B": "4", "C": "2", "D": "6"}, "correct_answer": "A"},
    {"id": 17, "difficulty": "easy", "question": "Cuboid with all sides equal is a? 🔲", "options": {"A": "Cube", "B": "Sphere", "C": "Cylinder", "D": "Cone"}, "correct_answer": "A"},
    {"id": 18, "difficulty": "easy", "question": "1 liter = ? cm³ 💧", "options": {"A": "1000", "B": "100", "C": "10", "D": "10000"}, "correct_answer": "A"},
    {"id": 19, "difficulty": "easy", "question": "Sphere radius 10.5cm. Diameter? 📏", "options": {"A": "21 cm", "B": "10.5 cm", "C": "31.5 cm", "D": "42 cm"}, "correct_answer": "A"},
    {"id": 20, "difficulty": "easy", "question": "Cone slant height formula? 🔺", "options": {"A": "√(r²+h²)", "B": "r+h", "C": "r²+h²", "D": "πr+h"}, "correct_answer": "A"},
    {"id": 21, "difficulty": "medium", "question": "Cuboid 15cm×12cm×10cm. Diagonal length? 📐", "options": {"A": "√(15²+12²+10²)=√469≈21.66 cm", "B": "15+12+10=37 cm", "C": "√(15²+12²)=√369≈19.2 cm", "D": "15×12×10=1800 cm"}, "correct_answer": "A"},
    {"id": 22, "difficulty": "medium", "question": "Cylinder radius 14cm, height 20cm. TSA? 📏", "options": {"A": "2π×14(20+14)=2992 cm²", "B": "2π×14×20=1760 cm²", "C": "π×14²×20=12320 cm³", "D": "π×14²=616 cm²"}, "correct_answer": "A"},
    {"id": 23, "difficulty": "medium", "question": "Sphere volume 38808 cm³. Radius? 🔍", "options": {"A": "∛[(38808×3)/(4π)]=21 cm", "B": "√(38808/4π)=55 cm", "C": "38808/(4π)=3087 cm", "D": "∛38808=33.8 cm"}, "correct_answer": "A"},
    {"id": 24, "difficulty": "medium", "question": "Cone radius 7cm, slant height 25cm. Volume? 🍦", "options": {"A": "h=√(25²-7²)=24, V=(1/3)π×7²×24=1232π cm³", "B": "(1/3)π×7²×25=1225π/3 cm³", "C": "π×7×25=175π cm²", "D": "π×7²×25=1225π cm³"}, "correct_answer": "A"},
    {"id": 25, "difficulty": "medium", "question": "Hemisphere TSA 462 cm². Radius? 🌓", "options": {"A": "3πr²=462, r=√(462/3π)=7 cm", "B": "2πr²=462, r=√(462/2π)=8.6 cm", "C": "πr²=462, r=√(462/π)=12.1 cm", "D": "4πr²=462, r=√(462/4π)=6.1 cm"}, "correct_answer": "A"},
    {"id": 26, "difficulty": "medium", "question": "Cube volume 729 cm³. Side length? 🔲", "options": {"A": "∛729=9 cm", "B": "√729=27 cm", "C": "729/6=121.5 cm", "D": "729/12=60.75 cm"}, "correct_answer": "A"},
    {"id": 27, "difficulty": "medium", "question": "Cylinder CSA 440 cm², height 10cm. Volume? 🔄", "options": {"A": "r=440/(2π×10)=7, V=π×7²×10=1540 cm³", "B": "440×10=4400 cm³", "C": "π×10²×440/(2π×10)=2200 cm³", "D": "440²/(4π×10)=1540 cm³"}, "correct_answer": "A"},
    {"id": 28, "difficulty": "medium", "question": "Cone height 12cm, volume 100π cm³. Radius? 📊", "options": {"A": "√[(100π×3)/(π×12)]=√25=5 cm", "B": "100π/(π×12)=8.33 cm", "C": "√(100/12)=2.89 cm", "D": "100×3/12=25 cm"}, "correct_answer": "A"},
    {"id": 29, "difficulty": "medium", "question": "Sphere SA 154 cm². Volume? ⚫", "options": {"A": "r=√(154/4π)=3.5, V=(4/3)π×3.5³≈179.67 cm³", "B": "154×3.5/3=179.67 cm³", "C": "154 cm³", "D": "√154×π=38.5 cm³"}, "correct_answer": "A"},
    {"id": 30, "difficulty": "medium", "question": "Cuboid TSA 94 cm², dimensions 3cm×4cm×5cm. Verify? ✅", "options": {"A": "2(3×4+4×5+5×3)=94 ✓", "B": "3×4×5=60 ✗", "C": "3+4+5=12 ✗", "D": "2(3+4+5)=24 ✗"}, "correct_answer": "A"},
    {"id": 31, "difficulty": "medium", "question": "Cylinder volume 2156 cm³, height 14cm. CSA? 📐", "options": {"A": "r=√(2156/(π×14))=7, CSA=2π×7×14=616 cm²", "B": "2156/14=154 cm²", "C": "π×14²=616 cm²", "D": "2π×14×√(2156/π×14)=880 cm²"}, "correct_answer": "A"},
    {"id": 32, "difficulty": "medium", "question": "Cone CSA 550 cm², radius 7cm. Slant height? 🔺", "options": {"A": "550/(π×7)=25 cm", "B": "√(550/π)=13.2 cm", "C": "550/7=78.6 cm", "D": "7+√(550/π)=20.2 cm"}, "correct_answer": "A"},
    {"id": 33, "difficulty": "medium", "question": "Hemisphere volume 19404 cm³. Radius? 🌓", "options": {"A": "∛[(19404×3)/(2π)]=21 cm", "B": "√(19404/π)=78.6 cm", "C": "19404/(2π)=3087 cm", "D": "∛19404=26.9 cm"}, "correct_answer": "A"},
    {"id": 34, "difficulty": "medium", "question": "Cube diagonal 10√3 cm. Volume? 🔷", "options": {"A": "side=10, V=1000 cm³", "B": "side=10√3, V=3000√3 cm³", "C": "side=5√3, V=375√3 cm³", "D": "side=10/√3, V=1000/(3√3) cm³"}, "correct_answer": "A"},
    {"id": 35, "difficulty": "medium", "question": "Cylinder radius doubled, height halved. Volume change? ⚖️", "options": {"A": "Doubles", "B": "Same", "C": "Halves", "D": "Quadruples"}, "correct_answer": "A"},
    {"id": 36, "difficulty": "medium", "question": "Sphere radius increased by 20%. Volume increase %? 📈", "options": {"A": "72.8%", "B": "20%", "C": "44%", "D": "100%"}, "correct_answer": "A"},
    {"id": 37, "difficulty": "medium", "question": "Cone radius 5cm, height 12cm. TSA? 📏", "options": {"A": "l=√(5²+12²)=13, π×5(13+5)=90π cm²", "B": "π×5×13=65π cm²", "C": "π×5²+π×5×13=90π cm²", "D": "π×5×12=60π cm²"}, "correct_answer": "A"},
    {"id": 38, "difficulty": "medium", "question": "Cuboid volume 240 cm³, sides ratio 3:4:5. Sides? 📦", "options": {"A": "3x×4x×5x=60x³=240, x=∛4≈1.59, sides≈4.77,6.36,7.95 cm", "B": "3,4,5 cm", "C": "6,8,10 cm", "D": "9,12,15 cm"}, "correct_answer": "A"},
    {"id": 39, "difficulty": "medium", "question": "Cylinder TSA 1188 cm², height 15cm. Radius? 🛢️", "options": {"A": "2πr(15+r)=1188, r=7 cm", "B": "1188/(2π×15)=12.6 cm", "C": "√(1188/π)=19.5 cm", "D": "1188/15=79.2 cm"}, "correct_answer": "A"},
    {"id": 40, "difficulty": "medium", "question": "Sphere fits exactly in cube side 14cm. Sphere volume? 🎲", "options": {"A": "r=7, V=(4/3)π×7³=(1372/3)π cm³", "B": "r=14, V=(4/3)π×14³", "C": "Cube volume=2744 cm³", "D": "r=7, V=4π×7²=196π cm²"}, "correct_answer": "A"},
    {"id": 41, "difficulty": "hard", "question": "Cone radius 6cm, height 8cm cut at mid-height. Volume of smaller cone? 🔪", "options": {"A": "(1/8) of original = (1/8)×96π=12π cm³", "B": "(1/3)×96π=32π cm³", "C": "Half=48π cm³", "D": "(1/27)×96π=3.56π cm³"}, "correct_answer": "A"},
    {"id": 42, "difficulty": "hard", "question": "Cylinder radius 10cm contains water. Sphere radius 5cm immersed. Water rise height? 💧", "options": {"A": "(4/3)π×5³ ÷ (π×10²)=5/3≈1.67 cm", "B": "5 cm", "C": "10 cm", "D": "2.5 cm"}, "correct_answer": "A"},
    {"id": 43, "difficulty": "hard", "question": "Hemisphere melted into cone radius 7cm, height 24cm. Hemisphere radius? ♻️", "options": {"A": "(2/3)πR³=(1/3)π×7²×24, R=√(7²×12)=√588≈24.25 cm", "B": "R=7 cm", "C": "R=14 cm", "D": "R=21 cm"}, "correct_answer": "A"},
    {"id": 44, "difficulty": "hard", "question": "Cuboid 30×20×15cm has cylindrical hole radius 7cm through center. Remaining volume? 🕳️", "options": {"A": "9000 - π×7²×15=9000-735π≈6691.5 cm³", "B": "9000 - π×7²×30", "C": "9000 + π×7²×15", "D": "π×7²×15=735π cm³"}, "correct_answer": "A"},
    {"id": 45, "difficulty": "hard", "question": "Sphere radius 10.5cm fits in cylinder. Minimum cylinder volume? 📦", "options": {"A": "π×(10.5)²×21=π×110.25×21≈7276.5π cm³", "B": "(4/3)π×10.5³=1543.5π cm³", "C": "π×10.5²×10.5=1157.625π cm³", "D": "π×21²×21=9261π cm³"}, "correct_answer": "A"},
    {"id": 46, "difficulty": "hard", "question": "Cone CSA 4070 cm², diameter 42cm. Height? 📐", "options": {"A": "l=4070/(π×21)≈61.8, h=√(61.8²-21²)≈58.1 cm", "B": "h=42 cm", "C": "h=21 cm", "D": "h=√(42²-21²)=36.4 cm"}, "correct_answer": "A"},
    {"id": 47, "difficulty": "hard", "question": "Cylinder radius 14cm, height 20cm painted at ₹0.10/cm². Cost? 🎨", "options": {"A": "TSA=2π×14(20+14)=2992 cm², cost=₹299.2", "B": "CSA only=1760 cm², cost=₹176", "C": "₹500", "D": "₹350"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "hard", "question": "Sphere volume 179.67π cm³. Material cost at ₹5/cm³? 💰", "options": {"A": "V≈179.67π≈564.5 cm³, cost≈₹2822.5", "B": "₹898.35", "C": "₹1796.7", "D": "₹5645"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "hard", "question": "Cone radius 5cm, height 12cm inscribed in cylinder. Cylinder volume? 🔄", "options": {"A": "Same radius & height: π×5²×12=300π cm³", "B": "π×5²×13=325π cm³", "C": "π×12²×5=720π cm³", "D": "π×6²×12=432π cm³"}, "correct_answer": "A"},
    {"id": 50, "difficulty": "hard", "question": "Hemisphere bowl radius 21cm holds liquid. Volume in liters? 🍵", "options": {"A": "(2/3)π×21³=6174π≈19404 cm³=19.404 liters", "B": "9.702 liters", "C": "38.808 liters", "D": "29.106 liters"}, "correct_answer": "A"},
    {"id": 51, "difficulty": "hard", "question": "Cube side 8cm with sphere inscribed. Ratio of volumes? ⚖️", "options": {"A": "Sphere: Cube = (4/3)π×4³ : 8³ = 256π/3 : 512 = π:6", "B": "π:3", "C": "π:4", "D": "π:2"}, "correct_answer": "A"},
    {"id": 52, "difficulty": "hard", "question": "Cylinder radius 7cm, height 10cm melted into cones radius 3.5cm, height 4cm. How many? ♻️", "options": {"A": "(π×7²×10) ÷ [(1/3)π×3.5²×4]=30", "B": "15", "C": "20", "D": "45"}, "correct_answer": "A"},
    {"id": 53, "difficulty": "hard", "question": "Cone TSA 704 cm², radius 7cm. Volume? 📊", "options": {"A": "l=(704/π×7)-7=25, h=√(25²-7²)=24, V=(1/3)π×7²×24=1232π cm³", "B": "704 cm³", "C": "1232 cm³", "D": "2464π cm³"}, "correct_answer": "A"},
    {"id": 54, "difficulty": "hard", "question": "Sphere radius increased from 7cm to 10.5cm. SA increase %? 📈", "options": {"A": "(4π×10.5² - 4π×7²)/(4π×7²)×100=125%", "B": "50%", "C": "100%", "D": "225%"}, "correct_answer": "A"},
    {"id": 55, "difficulty": "hard", "question": "Cuboid 60×40×30cm has 4 cylindrical pillars radius 14cm, height 3m. Total volume? 🏢", "options": {"A": "Cuboid:72000 cm³, Pillars:4×π×14²×300=4×1848×300=2217600 cm³, Total=2289600 cm³", "B": "72000+739200=811200 cm³", "C": "Only pillars volume", "D": "Cuboid volume only"}, "correct_answer": "A"},
    {"id": 56, "difficulty": "hard", "question": "Cone radius 10cm, height 24cm cut into 3 equal heights. Middle frustum volume? 🍰", "options": {"A": "Vol of cone height 16 - cone height 8 = (1/3)π×10²×(16-8)×(similarity factor)", "B": "1/3 of total", "C": "Middle=19/27 of total", "D": "Same as top"}, "correct_answer": "A"},
    {"id": 57, "difficulty": "hard", "question": "Cylinder height 21cm, CSA 1848 cm². Weight if density 8g/cm³? ⚖️", "options": {"A": "r=1848/(2π×21)=14, V=π×14²×21=12936 cm³, weight=103.488 kg", "B": "21×1848=38808 g", "C": "1848×8=14784 g", "D": "12936×8=103488 g=103.488 kg"}, "correct_answer": "A"},
    {"id": 58, "difficulty": "hard", "question": "Sphere radius 14cm coated with thickness 0.1cm. Coating volume? 🎨", "options": {"A": "(4/3)π×(14.1³-14³)≈(4/3)π×(2803.22-2744)≈248.8 cm³", "B": "4π×14²×0.1=246.4 cm³", "C": "4π×14.1²×0.1=249.9 cm³", "D": "π×14²×0.1=61.6 cm³"}, "correct_answer": "A"},
    {"id": 59, "difficulty": "hard", "question": "Cone, hemisphere same radius. Height ratio for equal volume? ⚖️", "options": {"A": "(1/3)πr²h=(2/3)πr³ ⇒ h=2r", "B": "h=r", "C": "h=3r", "D": "h=r/2"}, "correct_answer": "A"},
    {"id": 60, "difficulty": "hard", "question": "Metallic sphere radius 9cm drawn into wire radius 0.3cm. Length? 🧵", "options": {"A": "[(4/3)π×9³] ÷ (π×0.3²)=10800 cm=108 m", "B": "360 m", "C": "54 m", "D": "216 m"}, "correct_answer": "A"}
  ]
}