Peggy had three times as many quarters as nickels. She had $1.60 in all. How many nickels and how many quarters did she have? Which of the following equations could be used to solve the problem?

Let q and n represent the number of quarters and nickels respectively.

q=3n and. 05n+.25q=1.6 These are the conditions in mathematical terms.

To solve, use the value of q from the first equation in the second equation to get:

.05n+.25 (3n) = 1.6 carry out indicated multiplication on left side

.05n+.75n=1.6 combine like terms on left side

.8n=1.6 divide both sides by. 8

n=2, since q=3n

q=6

So Peggy had 2 nickels and 6 quarters.