2 pipes can separately fill a tank in 20hrs and 30hrs respectively

2 pipes can separately fill a tank in 20hrs and 30hrs respectively. Both the pipes are opened to fillthe tank, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?

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 #74355