Multiple choice

If the radius of the base and the height of a right circular cone are increased by 25%, then what is the approximate percentage increase in volume? यदि एक लंबवृत्तीय शंकु की आधार त्रिज्या और ऊँचाई में 25% की वृद्धि कर दी जाती है, तो उसके आयतन में लगभग प्रतिशत वृद्धि क्या होगी?

  1. 95

  2. 68

  3. 73

  4. 75
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cone volume V = (1/3)πr²h. After 25% increase: r' = 1.25r, h' = 1.25h. New volume V' = (1/3)π(1.25r)²(1.25h) = (1.25)³ × (1/3)πr²h = 1.953125V. Percentage increase = (1.953125 - 1) × 100 ≈ 95%. Options like 68% would come from using 1.25 × 2 = 2.5 incorrectly instead of 1.25³.

Keep practicing — related questions