Multiple choice

Radius of a cone is increased by 20% and its height is reduced by 10%. Find the percentage change in its volume. एक शंकु के त्रिज्या में 20% की वृद्धि की गयी और इसकी ऊंचाई में 10% की कमी की गयी । इसके आयतन में प्रतिशत परिवर्तन ज्ञात कीजिये।

  1. increased by 29.6% 29.6% की वृद्धि

  2. reduced by 29.6% 29.6% की कमी

  3. increased by 32.6% 32.6% की वृद्धि

  4. reduced by 32.6% 32.6% की कमी

  5. None of these इनमे से कोई नहीं
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Volume of cone V = (1/3)πr²h. New radius = 1.2r (20% increase). New height = 0.9h (10% decrease). New volume V' = (1/3)π(1.2r)²(0.9h) = (1/3)π × 1.44r² × 0.9h = 1.296 × (1/3)πr²h = 1.296V. Percentage change = (1.296V - V)/V × 100 = 0.296 × 100 = 29.6% increase.

Keep practicing — related questions