Word problem algebra.

Question

Sarah has been saving quarters and nickels. She opened up her piggy bank and determined that it contained 44 coins worth $4.80. Determine how many quarters and nickels are in her piggy bank

Answer 1

.05n + .25q = 4.80

 

n + q = 44

 

By substitution:

 

.05(44-q) + .25q = 4.80

 

2.2 - .05q + .25q = 4.80

 

2.2 + .2q = 4.80

 

.2q = 2.6

 

q = 2.6/.2 = 13

 

Since q + n = 44, n = 44 - q = 31

 

so there are 13 quarters and 31 nickels

 

Check

 

13(.25) + 31(.05) = 4.80