Starting on the day Shawn was born, her mother has invested $20 at the beginning of every month in a savings account that earns 1.60% compounded monthly.

a. How much did Shawn have in this account on her 18th birthday? Assume that there was no deposit on that day. (Round to the nearest cent)

b. What was her mother's total investment? (Round to the nearest cent)

c. How much interest did the investment earn? (Round to the nearest cent)