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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?
- A62
- B56
- C48
- D52
Answer not set
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CCommunity
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%
⇒ 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%