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?

If the variable n represents the number of nickels, then which of the following expressions represents the number of quarters?

She has 6 quarters.

3n; 2 nickels and 6 quarters

Step-by-step explanation:

"Peggy had three times as many quarters as nickels."

Whatever number of nickels she has, the number of quarters is 3 times as many.

Since she has n nickels, she has 3 times n quarters.

The number of quarters is 3n.

A nickel is worth $0.05, so n nickels are worth 0.05n.

A quarter is worth $0.25, so 3n quarters are worth 0.25 (3n).

0.05n + 0.25 (3n) = 1.60

0.05n + 0.75n = 1.6

0.8n = 1.6

n = 2

She has 2 nickels.

3n = 3 (2) = 6

She has 6 quarters.