A and B together can do a work in 5 days

A and B together can do a work in 5 days. If A alone can do it in 15 days. In how many days can B alone do it?

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 #12488