Machines A and B produce bottles at their respective constant rates

Machines A and B produce bottles at their respective constant rates. Machine A produces k bottles in 4 hours and machine B produces k bottles in 7 hours. How many hours does it take machines A and B, working simultaneously, to produce 22k bottles?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #53968