Question

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?

Answer 1

0.05n + 0.25q = 1.60
q = 3n

0.05n + 0.25(3n) = 160
0.05n + 0.75n = 1.60...multiply by 100 to get rid of the decimals
5n + 75n = 160...answer D

Answer 2

To answer the question, let the number of nickels Peggy has be n. By this, the Peggy has 3n quarters. The total amount of all his nickels and quarter is equal to $1.60. The equation that best describe the situation is, 
                            25(3n) + 5(n) = 160
Simplification leads to,
                             75n + 5n = 160
Thus, the answer is letter D.