A cylindrical hole of depth 20 m with a radius 5 m is dug from

a-cylindrical-hole-of-depth-20-m-with-a-radius-5-m-is-dug-from

A cylindrical hole of depth 20 m with a radius 5 m is dug from the earth forming a platform of length 14 m and a breadth of 12 m. Find the height of the platform.

A. 8.34 m^3

B. 11.84 m^3

C. 7.64 m^3

D. 9.34 m^3

I had been asked this question by my school principal while I was bunking the class.

This key question is from Conversion of Solid from One Shape to Another in portion Surface Area and Volumes of Mathematics – Class 10

Right choice is D. 9.34 m^3

To elaborate: Volume of the cylindrical hole = volume of the platform

πr^2h = lbh

3.14 × 5^2 × 20 = 14 × 12 × h

h = 9.34 m^3