InterviewSolution
Saved Bookmarks
| 1. |
A right circular cylinder has height 18 cm and radius 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?1). 622). 563). 484). 52 |
|
Answer» Total surface area before the cut = 2πrh + 2πr2 ⇒ 2πr(r + h) ⇒ 2 × 22/7 × 7 × 25 = 1100 cm2 After CUTTING in 3 EQUAL parts by 2 cuts PARALLEL to the base, curved surface area will not increase only base area will increase, ⇒ Increase in base area = 4πr2 = 4 × 22/7 × 7 × 7 = 616 cm2 ∴ Percentage increase in total surface area = 616/1100 × 100 = 56% |
|