Question

if a car uses 1/3 of a tank of petrol on the first part of the journey then 2/5 of a tank of petrol on the second part on the journey and has 8 litres how many litres of petrol did it have before the journey

Answer 1

We assume the petrol tank was full at the beginning of the journey.

The petrol tank holds x litres.

x - 1/3 x - 2/5 x = 8

15x/15 - 5x/15 - 6x/15 = 8

4x/15 = 8

4x = 120

x = 30

The petrol tank holds 30 litres.