In a certain state, gasoline stations compute the price per gallon p, in dollars, charged at the pump by adding a 3 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 choice from the following answers:
A) d = (p-0.03)/1.18 B) d = p/1.21 C) d= (p-0.18)/1.03 D) d = p-0.20 E) d = p/1.03 - 0.18
Let dealers price (d) be 1. so adding 3% to dealers price is d+ 3% of d. i.e. 1 + 3% of 1 which is1 + 0.03. then add 0.18 to the value.   Now 1.03 + 0.18. this is now 1.21. you have the gasoline stations price (p) as 1.21 dollars.   Now sub 1.21 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)/1.03
<result>C</result>
In a certain state, gasoline stations compute the price per gallon p, in dollars, charged at the pump by adding a 3 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?