A does a work in 20days and B does the same work…

A does a work in 20days and B does the same work in 5days. In how many days they together will do the same work?

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 #9514