15 litres of mixture contains 20% alcohol and the rest water

15 litres of mixture contains 20% alcohol and the rest water. If 2litres of water be mixed with it, the percentage of alcohol in the new mixture would be?

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 #13013