Murphy and Cooper are having the same amount of petrol in the…

Murphy and Cooper are having the same amount of petrol in the petrol tanks of their respective cars. Murphy can drive for four hours with that amount whole Cooper can drive for five hours. They both starts together and keep driving for a few hours. After some time, they find that the amount of petrol remaining in one car is four times that of the other car. Using all these facts, can you find out how long they drove their cars?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #56114