Question

A collection of dimes and quarters worth $9.25. There are 46 coins in all. Find how many of each there are. How many dimes are there?

Answer 1

Let d represent the number of dimes. Then the value of the coins can be written as ...
0.10d +0.25(46 -d) = 9.25
-0.15d = 9.25 -(0.25*46) = -2.25 . . . . simplify, subtract .25*46
d = 2.25/.15 = 15 . . . . . . . . . . . . . . . . . divide by the coefficient of d

There are 15 dimes.