Astorage container is in the shape of a rectangular prism with a length of 3 1/5 feet and a width of 1 3/4 feet and a height of 2 and 1/4 feet what is the container is volume

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.