A can do a piece of work in 10 days; B can…

A can do a piece of work in 10 days; B can do the same in 20 days. How many days will it take the work to get finished if A and B 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 #17176