I could use some help with assisting my son with his simple and compound interest middle school math homework. Any guidance is appreciated!

1. Ethan has saved $1800, however the guitar he wants costs double that (so, $3600).If Ethan invests his $1800 dollars for 10 years at a compounded interest rate of 6%, how much money will he have after 10 years?
2. After saving for 10 years, does Ethan have enough to buy that guitar?
3. You take out a $30,000 loan at 2.9% interest compounded annually for 10 years.If you do not make any payments for 10 years, how much will you owe at the end?
4. You take out a loan for $30,000 for 10 years at 3.8% simple interest.What is the total amount you will pay?(Remember you have to add the principal and the interest).
5. You take out a loan for $30,000 for 7 years at 5.1% simple interest.What is the total you will pay?
6. You take out a loan for $30,000 for 8 years at 3.9% compound interest for 8 years.If you do not make any payments until the end of 8 years, how much will you owe?
7. Look at your answers for Questions 3, 4, 5, and 6. Which interest rate and time period will result in the lowest total loan repayment for a $30,000 loan earning interest?

a. Question 3: 2.9% compound interest for 10 years

b. Question 4: 3.8% simple interest for 10 years

c. Question 5: 5.1% simple interest for 7 years

d. Question 6: 3.9% compound interest for 8 years

8. Marisa invested $3,000 for 8 years at 4.5% simple interest. How much interest will Marisa earn?

9.Miguel invested $3,000 for 8 years at 4.5% compounded annually. How much interest will Miguel earn?

10. How much more interest will Miguel earn than Marisa?