The average runs scored by a batsman in 15 matches is 30

The average runs scored by a batsman in 15 matches is 30. In the next 20 matches the batsman scored an average of 15 runs. Find his average in all the 30 matches?

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 #58567