In a class, there are 20 boys whose average age is decreased…

In a class, there are 20 boys whose average age is decreased by 2 months, when one boy aged 16 years replaced by a new boy. The age of the new boy 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 #9120