Question

A collection of dimes and quarters has a total value of three dollars and eighty-five cents and contains 25 coins. How many dimes are there in the collection?A) 12 dimesB) 5 dimesC) 16 dimesD) 9 dimes

Answer 1

Let x be the number of dimes and y be the number of quarters

=> x + y = 25

=> 0.25x + 0.1y = 3.85

=> 0.25x + 0.1(25 - x) = 3.85

=> 0.25x + 2.5 - 0.1x = 3.85

=> 0.25x - 0.1x = 3.85 - 2.5

=> 0.15x = 1.35

=> x = 9

The correct option is D.