Volume of cylinder is given by: V=πr²h where: r=radius h=height suppose the radius of the large cylinder is r, since the cylinder has been filled with the 5 balls, the height of the cylinder is: 5d where d is the diameter of one ball, but d=2r: hence the height will be:5(2r)=10r Thus the volume of the cylinder will be: 3925=3.14×r²×10r 3925=31.4r³ hence solving for r we shall obtain: r³=125 hence r=∛125 r=5 cm
