Answer: Assume any constant for the diameter of a ball is D.
The height of the 3 balls will then be 3D.
The circumference is Pi D which is approximately 3.14 D.
Thus the circumference is greater.
Since you do not specify the amount of air space between the balls and the top of the can, there is no valid solution to the problem stated. But the height of 3 balls is not as great as the circumference of one ball.
