Helppp please i need this asap

Diane’s bank is offering 5% interest, compounded monthly. if diane invests $10,500 and wants $20,000 when she withdrawals, how long should she keep her money in for? round to the nearest tenth of a year.

Mr.walker is looking at the fundraiser totals for the last five years , how does the mean of the totals compare to the median?

I’m still confused on how to work the percentages