I need help with problems 2 and 3. Thank you!

2. a) A Discount Bond with a Face Value of $2,000 and a 10-year maturity has what interest rate when purchased for $1,600? b) if this bond had a 5-year maturity what would be the interest rate? (use the easy way) 3. What is the interest rate on a simple loan of $400 that pays back $480 in 5 years? (use the easy way)