227k views
5 votes
A box of 80 coins, consisting of only nickels and dimes, is worth 7 dollars and 80 cents. Find the number of nickels.

User Jivago
by
6.6k points

1 Answer

7 votes
4 nickles
Step-by-step explanation:
80=N+D
7.80=0.05N + 0.1D

D=80-N

7.80=0.05N + 0.1(80-N)
7.80=0.05N + 8 - 0.1N
0.1N + 7.80 = 8 + 0.05N
0.05N = 8-7.80
0.05N = 0.2
N= 4
User Brkr
by
6.0k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.