A can do a piece of work in 5 days and B…

A can do a piece of work in 5 days and B can do it in 4 days how long will they both work together to complete the 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 #7854