After replacing an old member by a new member, it was found…

After replacing an old member by a new member, it was found that the average age of five members of a club is the same as it was 3 years ago.What is the difference between the ages of the replaced and the new member?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #42759