– all either nickels, dimes or quarters.
Cookie has 97 coins in her collection
n+d+q = 97
If 77 of her coins are quarters and dimes
d+q=77
And also that implies that the other 97-77 or 20 coins are nickels.
So n = 20
the total value of her coins is $13.95
5n + 10d + 25q = 1395
So we have this system:
Substitute n=20
Simplify
Simplify and delete duplicate equation:
Solve that system and get d=42,q=35
Solution: 20 nickels, 42 dimes, 35 quarters.
Edwin