2022 · Q70
A tall cylindrical container with circular base of radius 18 cm contains a good quantity of water. Metal balls each of radius 0.9 cm are immersed in it. How many balls are required to raise the water lever by 3 cm?
Elementary MathematicsMensuration
- A100
- B500
- C1000
- D1500
Explanation
Water to displace: πx18²x3 = 972π cm³; each ball displaces (4/3)π(0.9)³ = 0.972π cm³. Hence 972/0.972 = 1000 balls. Hence the keyed option is C.