Isaiah has $3.45 in dimes and quarters. If he has a total of 24 coins, how many dimes does he have? Write and solve a system of equations.

12

17

18

10

Let x and y be the number of dimes and quarters that Isaiah has. The sum of these variables should be 24 and the total value be $3.45. The equations that would best represent the situation are,

x + y = 24

0.1x + 0.25y = 3.45

The values of x and y are 17 and 7, respectively. Thus, the answer is the second choice.