Question

A jar contains 65 coins, all of which are nickels and dimes. The total value of the coins in the jar is $5.40. How many nickels / dimes are in the jar?

Answer 1

43 dimes, 22 nickels

Explanation:

n + d = 65....this is just dealing with the total number of coins

0.05n + 0.10d = 5.40....this is dealing with the actual $ amount...nickels are worth 0.05 and dimes are worth 0.10

n + d = 65....n = 65 - d

now we sub that back into our other equation

0.05(65 - d) + 0.10d = 5.40

3.25 - 0.05d + 0.10d = 5.40

-0.05d + 0.10d = 5.40 - 3.25

0.05d = 2.15

d = 2.15 / 0.05

d = 43 <==== 43 dimes

n + d = 65

n + 43 = 65

n = 65 - 43

n = 22 <=== 22 nickels