Which function does not represent exponential growth? y= 3(0.2)^x y= 3(2)^x y= 0.3(2)^x y=0.2(3)^x

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.