A right circular cylinder has height as 18 cm and radius as 7 cm. The cylinder is cut in three equal parts (by 2 cuts parallel to base). What is the percentage increase in total surface area?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 56%
TSA of cylinder
= 2π × r (r + 7)
= 2π × 7 (7 + 18)
TSA of 3 new cylinders
= 3 × (2 × π × 7 × 6) + 3 × (2 × π × (7)2)
Difference = 4π (7)2
= 