If the height of a cylinder is increased by 25%, and the radius of its base is decreased by 15%, then find the percentage increase/decrease in its curved surface area.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. increases 6.25%.
C.S.A of cylinder = 2πrh
The net percentage change = x + y + xy/100
⇒ 25 - 15 - (25 × 15)/100
⇒ 10 - 375/100
⇒ 10 - 3.75 = 6.25% increament
Note:- Here, negative sign shows the decrement and positive sign shows the increament