Joel has $2.50 in his pocket. He has 7 more dimes than nickels. Now many of each coin does he have?

Answer 1

N = number of nickels

N + 7 = number of dimes

0.05*N = money from nickels

0.10*(N+7) = money from dimes

total money = 2.50

0.05*N + (N+7)*0.10 = 2.50

0.05*N + 0.10*N + 7*0.10 = 2.50

0.15*N + 0.70 = 2.50

0.15*N = 1.80

N = 12

N+7 = 19

12 nickels

19 dimes