Five years ago, the average age of A and B was 15…

Five years ago, the average age of A and B was 15 years. Average age of A, B and C today is 20 years. How old will C be after 12 years?

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 #30480