In a certain state, gasoline stations compute the price per gallon p, in dollars, charged at the pump by adding a 2 percent sales tax to the dealer's price per gallon d, in dollars, and then adding a gasoline tax of $0.18 per gallon. Which of the following gives the dealer's price per gallon d in terms of the price per gallon p charged at the pump?
Choose the correct answer
A) d = (p-0.02)/1.18	B) d = p/1.20	C) d = p/1.02 - 0.18	D) d= (p-0.18)/1.02	E) d = p-0.20
Let dealers price (d) be 1. so adding 2% to dealers price is d+ 2% of d. i.e. 1 + 2% of 1 which is1 + 0.02. then add 0.18 to the value.   Now 1.02 + 0.18. this is now 1.20. you have the gasoline stations price (p) as 1.20 dollars.   Now sub 1.20 in the options to know which option gave you d = 1. d must equal 1 because you earlier picked 1 as the value of d in the question.   PS: always remember to start from E upwards.   Answer : d= (p-0.18)/1.02
<result>D</result>
In a certain state, gasoline stations compute the price per gallon p, in dollars, charged at the pump by adding a 2 percent sales tax to the dealer's price per gallon d, in dollars, and then adding a gasoline tax of $0.18 per gallon. Which of the following gives the dealer's price per gallon d in terms of the price per gallon p charged at the pump?