volume of spherical ball = 4/3 22/7 r^3
which should be equal to raise in height of water
as displaced water volume = volume of our cricket ball.
22/7 * 7.5 (radius of cylindrical tank) ^2 * h (height) = 4/3 22/7 r^3
which equates to
h = 4/3 * 3.6^3 / 7.5^2