Answer:
62.05 for 15 gallons
Explanation:
Becauses its a better deal but only by a 1$
21$ or 5 gallons. So that deal is saying 21$ for 5 gallons so that deals 15 gallons is 63$ because you times 5 by 3 and that's the answer for that.
Say that 21$ for 5 gallons is at kroger and 62.05$ is at walmart.
walmart will be a better deal because your getting a dollar cheaper.
Walmart's 15 gallons=62.05$
Krogers=63$
So your answer is 62.05 for 15 gallons