John and David can finish a job together in 4 hours

John and David can finish a job together in 4 hours. If John can do the job by himself in 5 hours, what percent of the job does David do?

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 #35197