Question 1182928
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The difference in the price per gallon is 20 cents.<br>
If the car wash costs $7, then the number of gallons of gas you need to buy to save $7 on the gas is $7/$0.20 = 35.<br>
So it is worth getting the car wash if you are buying 35 gallons or more of gas.<br>
If the car wash costs $2, then the number of gallons of gas you need to buy to save $2 on the gas is $2/$0.20 = 10.<br>
So it is worth getting the car wash if you are buying 10 gallons or more of gas.<br>