Question
The height of a solid cylinder is 30 cm and the diameter
of its base is 10 cm. Two identical conical holes each of radius 5 cm and height 12 cm are drilled out. What is the surface area (in cm²) of the remaining solid?Solution
According to question: Height of cylinder = 30 cm Radius of cylinder = 5 cm Height of cone = 12 cm Radius of cone = 5 cm We know that, l2 = h2 + r2 ⇒ l2 = 122 + 52 ⇒ l2 = 144 + 25 ⇒ l = 13 cm The surface area of the remaining figure = surface area of cylinder + 2 × surface area of the cone ⇒ 2πrh + 2πrl ⇒ 2πr(h + l) ⇒ 2π × 5(30 + 13) ⇒ 430π ∴ The surface area of the remaining solid is 430π. 
(√1157 + 10.15% of 159.89) × 4.85 + 150.25 = ? × 19.67
{(√2305) % of 74.69} × 15.21 - 27.89 × 44.88 + 45.12% of 2399.87
(9116.89 – 8024.89 + 902.95) × 14 = 1800 × ?
(124.99)² = ?
? * 4.89 = (410.15 ÷ 13.97) % of 6190 - 1342.77
181.87 ÷ 13.89 X 8.13 + ? = 11.852Â
(√845 ×19.932+ √4230 ×14.385)/(√1765 ×4.877 ) = ?
180.25 × 14.995 ÷ √26 = ? × 5.985
1224.86% of √6399.98 = (399.99/4.99)% of (? ÷ 6.91 + 39.87)Â
24.11% of 249.99 + √143.97 ÷ 12.02 = ?
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