Answer:
It will cost $18 to put 15 liters of gas into your car.
Step-by-step explanation:
We have to find the unit price first, or the price per gallon. To find that, we would do $90 divided by 75 liters, which gives us $1.2 per gallon. Then, to find the price we have to pay for 15 liters, we would do 1.2 multiplied by 15, which is 18! :)