Answer :
Since there are 3 and assuming that they're the same size each radius is 1.5, as is the radius of the base of the cylinder. So you have to figure out the volume of one of the balls and multiply it by three. Formula: (4/3) * pi * radius^3. The volume of all three is 42.42. Then you need to find the volume of the cylinder. formula: pi * h * r^2. So it is 63.62. You now take this measure and subtract the volume of the three balls: 21.2in^3. To find the percentage, take 21.2/63.62. Then multiply by 100. The answer is 33.32, so your final answer is A.