Kevin and Randy Muise have a jar containing 84 coins, all of which are either quarters or nickels. The total value of the coins in the jar is ​$13.60. How many of each type of coin do they​ have?

Answer 1

Use cents to eliminate need for decimals.

25Q + 5N = 1360 where Q = no. of quarters and N = no. of nickels.

Q + N = 84, so Q = 84 - N

25(84 - N) + 5N = 1360

2100 - 25N + 5N = 1360

740 = 20N

N = 37, so Q = 47

Check: 5(37) + 25(47) = 185 + 1175 = 1360