Teresa has $3.60 in quarters and nickels. If she has 36 coins total, the number of quarters multiplies by the number of nickels is equal to what number?

Question

A) 128

B) 324

C) 315

D) 243

E) None of those

Answer 1

Suppose she has q quarters and n nickels

q + n = 36

25q + 5n = 360, so 5q + n = 72.

q + n = 36 (1)

5q + n = 72 (2)

Subtract (1) from (2) and then solve for q

Knowing q find n

Multiply q and n together.