A spherical ball of radius 3 cm is melted and recast into three spherical balls. The radii of two of the balls are 1.5 cm and 2 cm. Find the diameter of the third ball.

Let the radius of third sphere be r3


Volume of big spherical ball=volume of all three balls



R3 = r13 + r23 + r33


3 × 3 × 3 = (1.5 × 1.5 × 1.5) + (2 × 2 × 2) + r33


r33 = 27 - (3.375 + 8)


r33=15.625


r3=


r3=2.5 cm


27