нашел оригинал вопроса, там немного подробнее
You have a balance beam, the kind of scale that tips from one side to the other, depending on the weight on each side. On each side is a beaker, half-filled with water. The sides are in balance. Now, on the left side, you submerge a ping-pong ball suspended by a string. On the right side, you submerge a steel ball of the same volume as the ping-pong ball suspended from a crane.
так что я за свой первый ответ:
левая чаша перевесит