How many nickels, dimes, and quarters are in the piggy bank?

Question

There are some nickels, dimes, and quarters in a large piggy bank. For every 2 nickels, there are 3 dimes. For every 2 dimes, there are 5 quarters. There are 500 coins in total.

Answer 1

Let n, d, q be the number of nickels, dimes and quarters.

So n+d+q=500.

d=3n/2; q=5d/2=(5/2)(3n/2)=15n/4.

So n+3n/2+15n/4=500.

(4n+6n+15n)=2000.

25n=2000, n=80, d=120, q=300.

80 nickels, 120 dimes, 300 quarters.

Answer 2

2 nickels 6 dimes 15 quarters