learn.thinkwell.com/twtest/exercise.cfm 11 of 12 QID: 72060 Eddie spills his cash register drawer on the floor and has to sweep up the coins. He has 826 coins, which are a mixture of pennies, nickels, dimes, and quarters. There are 10 times as many pennies as dimes, and half as many quarters as dimes. If he has $\$ 36.80$, how many dimes are there? Enter your answer in the space provided below. Do not include unit measures.

Step 1 ：Let's denote the number of pennies as p, the number of nickels as n, the number of dimes as d, and the number of quarters as q. We then have the following equations:

Step 2 ：1. \(p + n + d + q = 826\) (total number of coins)

Step 3 ：2. \(0.01p + 0.05n + 0.10d + 0.25q = 36.80\) (total value of coins)

Step 4 ：3. \(p = 10d\) (number of pennies is 10 times the number of dimes)

Step 5 ：4. \(q = 0.5d\) (number of quarters is half the number of dimes)

Step 6 ：We can substitute equations 3 and 4 into equations 1 and 2 to solve for d.

Step 7 ：Substituting equations 3 and 4 into equation 1, we get \(11.5d + n = 826\)

Step 8 ：Substituting equations 3 and 4 into equation 2, we get \(0.325d + 0.05n = 36.8\)

Step 9 ：Solving these equations, we find that \(d = 18\) and \(n = 619\)

Step 10 ：Final Answer: The number of dimes is \(\boxed{18}\)