Question:
The curved surface area of a cylinder is reduced by ____________ per cent if the height is half of the original height.
Solution:
50%
Explanation:
The CSA of cylinder with radius “r” and height “h” is 2πrh
When the height is halved, then new CSA is 2πr (h/2) = πrh
Hence, the percentage reduction in CSA = [(2πrh – πrh) (100)]/ 2πrh = 50%