Kaitlen has $2.25 in nickels and dimes. The number of dimes is 5 less than twice the number of nickels. Find the number of nickels.
Let x be the number of nickels. We know that the number of dimes is 5 less than twice the number of nickels, so the number of dimes is 2x−5. We also know that Kaitlen has $2.25 in nickels and dimes. This means that 0.05x+0.10(2x−5)=2.25. Solving for x, we get x=9. Therefore, Kaitlen has 9 nickels.