Question

Billy Bob has 23 coins that total $1.70. He found some nickels and dimes in the couch.

How many nickels and dimes did he find?

Answer 1

12 nickels

11 dimes

Explanation:

Let n = no. of nickels

d = no. of dimes

5n = value of nickels in cents

10d = value of dimes in cents

170 = total value in cents

(1) n + d = 23 (2) 5n + 10d = 170

d = 23 - n 5n + 10(23 - n) = 170

5n + 230 - 10n = 170

- 5n = - 60

n = 12 nickels

d = 23 - 12 = 11 dimes

Check: 12(5) + 11(10) = 60 + 110 = 170 cents or $1.70