Jenny wants to give her 14-year-old daughter $20,000 when she turns 18. how much does she need to put in the bank now if the interest rate is 10 percent per year?

let's suppose it's her birthday ( in a few days)

Considering the interest rate by the end of the period she would have to had gathered 18 000 in the account which represents whatever g sum she has put together in the first 3 years +10%of that sum+what she has to add in the forth year and so on so she can deposit the sum she's got so far