The radius and height of a solid cylinder is increases by 2% each. What is the percentage change in its curved surface area?
Answer & explanation
Correct answer: option 1
C.S.A. of cylinder = 2\(\pi \)rh
2% = \(\frac{1}{50}\)
Actual : New
Radius: 50 : 51
Height: 50 : 51
C.S.A. : 2\(\pi \)RH : 2\(\pi \)rh
: 502 : 512 = 2500 : 2601
⇒ C.S.A. increased by = 2601 - 2500 = 101
⇒ Increased percentage = \(\frac{101}{2500}\) × 100 = 4.04%