Suppose you have just enough money, in coins, to pay for a gallon of milk priced at $2.40. You have 12 coins, all quarters and dimes. Let q equal the number of quarters and d equal the number of dimes. Which system models the given information?
a. q d = 25, 12 q 10 d = 240
b. 10 d d = 240, 25 q q = 12
c. q d = 240, 25 q 10 d = 12
d. q d = 12, 25 q 10 d = 240
