Please Show Work!!!

1. Whats the future value of $100 after 3 years if it earns 8%, annual compounding?
2. Whats the present value of $100 to be received in 3 years if the interest rate is 8%, annual compounding?
3. What annual interest rate would cause $1,000 to grow to $2,000 in 8 years?
4. If a companys sales are growing at a rate of 7.2% annually, how long will it take sales to double?.
5. What is the present value of a 6-year, $100 ordinary annuity if the annual interest rate is 4%?