Question

Lawrence has 10 coins in his pocket. One coin is a quarter, and the others are all nickels or dimes. The coins are worth 90 cents. How many nickels and dimes does Lawrence having his pocket?

Answer 1

4 dimes 5 nickels since you have to leave one out

Answer 2

10-1 = 9 dimes and nickels

0.90 - 0.25 = 0.65 worth

N + d = 9

N=9-d

0.05N + 0.10D = 0.65

0.05(9-d) +0.10d = 0.65

0.45 - 0.05d +0.1d = 0.65

0.45 +0.05d = 0.65

0.05d = 0.20

d = 0.20/0.05

d = 4

4 dimes and 5 nickels