A can do a piece of work 20 days

A can do a piece of work 20 days. B can do work in 35 days. In how many days they will complete the work together?

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 #94119