$\"\"$

If a principal $\"\"$ is invested at an annual interest rate $\"\"$ compounded $\"\"$ times a year, then the balance $\"\"$ in the account after $\"\"$ years is given by

$\"\"$ .

$\"\"$

Find how much money they should invest .

Here $\"\"$ , $\"\"$ and $\"\"$ years.

Since money is compounded daily, $\"\"$ .

Consider $\"\"$ .

Substitute corresponding values in above formula. \ \

$\"\"$

$\"\"$ .

Couple should invest money is $\"\"$ .

$\"\"$

Couple should invest money is $\"\"$ .