No excel, please show work, thank you :)

You want to start saving for retirement. You think you can comfortably deposit $500 per month into an investment account. You believe the account will earn a 9.25% APR, compounded monthly. You expect to retire in about 45 years. (a) How much will you have when you retire if you make your contributions at the beginning of each month? (1.5 points) I (b) How much will you have when you retire if you make your contributions at the end of each month? (1.5 points) (c) What is the financial implication of altering your contribution timing (i.e., how much of a difference is there between the two account balances)? (1 point)