Fernando Alonso and Sebastian Vettel go for a car race

Fernando Alonso and Sebastian Vettel go for a car race. Before the start of race, both of them have the exactly same amount of fuel in their respective cars. With the given fuel Fernando can drive continuously for 4 hours while Vettel can drive 1 hour more. After some time they realize that amount of fuel left in Sebastian car is 4 times the fuel in Fernando car. For long have they been racing ?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · dev #221