Idon’t understand how to set up the equation and expressions, i pretty much need with everything

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

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.

What are the excluded values? m+5/mn+3m