Question 606474
Volume of cylinder - volume of three balls = volume of empty space.

Cylinder = pi*r^2*h

The height of cylinder = 3 times the diameter of the ball.
The radius of cylinder = radius of ball

= 3.14 * 1.25^2*7.5 =36.8 cu.in


Volume of 1 ball = 4/ 3 * pi* *r^3
=4/3 * pi* 1.25^3
=8.18 cu.in

3 balls  volume = 8.18 *3
= 24.54 cu.in

empty space = 36.8 - 8.18= 27.68 cu.in