36 liters of diesel fuel is worth €18. The tank of this pickup truck can hold 64 liters. How much does a full tank of diesel fuel cost? Think carefully first, then make a decision:
A liter of diesel costs 18 / 36 = 0.5 €. 64 liters of diesel fuel cost 0.5 X 64 = 32 €. So, the answer is 32.