Question

A cylindrical vessel of diameter 18cm contains water. If iron spherical balls of radius 3cm are immersed in water, then the number of balls required to raise the level of water by 4cm in the cylinder is: /

Answer 1

Vol. of water raised=n* vol. of balls
$\pi$$R^{2}$h=n*4/3$\pi r^{3}$
9*9*4=n*4/3*3*3*3
n=9!

CHEERS!