The average age of 15 men of a group is 15 years

The average age of 15 men of a group is 15 years. Out of these, the average age of 5 men is 15 years and that of the other 9 men is 16 years. The age of the 15th man is?

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 #71424