Alpha and Beta have same amount of petrol in their respective cars. Alpha can drive for 4 hours whereas Beta can drive for 5 hours with the amount of petrol left.

Both of them start driving at the same time. After a few hours, they find out that the amount of petrol remaining in one of the cars is four times the other car.

Can you calculate for how long did they drive the cars?

Labels: Difficulty Level 4/5, Maths Puzzles, Time Distance Problem