Question

5) The price of a gallon of gas was $4.00. The price went up by 10% and then went down by 10%. Antonio thinks that since the price both rises and falls by 10%, the price of a gallon of gas is back to $4.00. His teacher tells him that he is incorrect. Explain why Antonio's reasoning is incorrect. (1 point) Determine the price of a gallon of gas after the 10% rise and 10% fall. (1 point) Total of 2 points. *

Answer 1

Antonio is wrong because 10% of 4.00 is .40 and if the price goes up then the price is $4.40 and since the price is going down by ten percent, ten percent if $4.40 is .44 and therefore the price is $3.96.