how many nickels and quarters are there?

Question

Alycia opens her piggy bank to find only quartersquarters and nickelsnickels inside. She counts the coins and finds that she has 3434 coins totaling $3.903.90. How many quartersquarters were in the piggy bank, and how many nickelsnickels were in there?

Answer 1

n + q = 34    (nickels and quarters)   or   n=34-q

5n +25q = 390 cents

 

Substitution:   5(34-q) +25q=390, then solve for q

170-5q+25q=390

20q=220

q=11

and

n=34-11 so n=23