Working alone, pump A can empty a pool in 4 hours

Working alone, pump A can empty a pool in 4 hours. Working alone, pump B can empty the same pool in 6 hours. Working together, how many minutes will it take pump A and pump B to empty the pool?

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 #23143