Jamie has a collection of 78 nickels, dimes, and quarters worth $12.40. If the number of quarters isdoubled, the value becomes $22.15. How many of each type of coin does Jamie have?

9514 1404 393Answer:25 nickels14 dimes39 quartersStep-by-step explanation:Doubling the number of quarters increases the value by ...   22.15 -12.40 = 9.75 = 39×0.25The number of quarters is 39, which means the number of nickels and dimes is 78 -39 = 39, and their value is ...   12.40 -9.75 = 2.65Let d represent the number of dimes. Then 39-d is the number of nickels and we have ...   0.05(39 -d) +0.10(d) = 2.65   0.05d + 1.95 = 2.65 . . . . simplify   0.05d = 0.70 . . . . . . . . . . subtract 1.95   d = 14   39 -d = 25Jamie has 25 nickels, 14 dimes, and 39 quarters in the collection.