Q185
ArithmeticGeometry & Mensuration
Keeping the radius of a right circular cone same, if the height of its increased thrice, the volume of it will be increased by:
- a.100%
- b.200%
- c.300%
- d.400%
Answer: (B) 200%
With the radius fixed, the cone's volume $\frac{1}{3}\pi r^2 h$ is proportional to its height. Making the height three times the original makes the volume three times too, an increase of 200%. 300% confuses 'three times' with 'an increase of three times'.