Your brother has a jar of coins in his room. The jar has a total of 32 coins. There are some quarters and some dimes. There is a total of $6.35 in the jar. How many dimes are in the jar?

Answer 1

D + Q = 32

10D + 25Q = 635

10D + 10Q =320 subtract to eliminate one variable

15Q = 315

Q = 315/15 = 21 quarters

D =32-21 = 11 dimes

10(11) + 25(21) = 635

110 + 525 = 635