Miguel Rodriguez borrowed $\$ 300$ from his brother Julio to pay for books and tuition. He agreed to pay Julio in 6 months with simple annual interest at $6.6 \%$. a) How much will the interest amount to? b) What amount must Miguel pay Julio at the end of 6 months?

Step 1 ：The problem is asking for the interest amount that Miguel will have to pay Julio. To calculate this, we need to use the formula for simple interest which is: Interest = Principal * Rate * Time.

Step 2 ：In this case, the Principal is the initial amount of money that was borrowed or invested, which is $300.

Step 3 ：The Rate is the annual interest rate, which is $6.6\%$ or $0.066$ in decimal form.

Step 4 ：The Time is the length of time that the money is borrowed or invested for, which is 6 months or $0.5$ years.

Step 5 ：We can plug these values into the formula to calculate the interest: \(Interest = Principal * Rate * Time = 300 * 0.066 * 0.5\)

Step 6 ：Calculating the above expression gives us the interest amount.

Step 7 ：\(\boxed{9.9}\) is the interest that Miguel will have to pay Julio.