The average runs scored by a batsman in 20 matches is 40

The average runs scored by a batsman in 20 matches is 40. In the next 30 matches the batsman scored an average of 20 runs. Find his average in all the 50 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 #49145