The ratio of the radius of the base and the height of a solid cylinder is 2 : 3. If its volume is 202.125 cm2, then find the total surface area. (Take 
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Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 192.5 cm2
| Understanding | Application |
| Tricks |
The volume of the cylinder = πr2h = 202.125 cm2
⇒ 22/7 × 22x2 × 3x = 202.125 ⇒ x3 = 202.125 × 7/22 × 12 ⇒ x3 = 1414875/264000 ⇒ x3 = 343/64 ⇒ x = 7/4 |
| Now |
r = 7/4 × 2 = 7/2 & h = 7/4 × 3 = 21/4 The total surface area of the cylinder = 2πr(h + r) ⇒ 2 × 22/7 × 7/2(7/2 + 21/4) ⇒ 22{(14 + 21)4} ⇒ 22 × 35/4 ⇒ 11 × 35/2 |
| Hence | 192.5 |