A and B complete a work in 4 days

A and B complete a work in 4 days. A alone can do it in 8 days. If both together can do the work in how many days?

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 #19598