### Home > MC2 > Chapter 10 > Lesson 10.1.6 > Problem10-79

10-79.

Mary wants to have $8500$ to travel to South America when she is $21$. She currently has $6439$ in a savings account earning $4\%$ annual compound interest. Mary is $13$ now.

1. If Mary does not take out or deposit any money, how much money will Mary have when she is $15$?

Formula for compound interest:
$A = P\left(1 + r\right)^{n}$

$6439\left(1 + 0.04\right)^{2}$

$\6964.42$

2. Will Mary have enough money for her trip when she is $21$?

Find how much money Mary will have in $8$ years.

Is this amount enough?

Use the formula in (a).