The radius of right circular cylinder is 21 cm and its curved surface area is 5280 cm2. What is 20% of the volume?
Answer & explanation
Correct answer: option 1
C.S.A. = 2\(\pi \)rh
5280 = 2 × \(\frac{22}{7}\) × 21 × h
h = \(\frac{5280}{132}\) = 40 cm
Volume of cylinder = \(\pi \)r2h = \(\frac{22}{7}\) × 21 × 21 × 40
20% of volume = \(\frac{1}{5}\) × \(\frac{22}{7}\) × 21 × 21 × 40 = 11088 cm3