John has $825 in his savings account. he has decided to deposit $65 per month until he has a total of $1800. in how many months will this occur

It would take 15 months, hope this helps

In 15 months.
He wants to save up $1800, but has $825 already so you subtract it which is $975. He has to save up $975 and he deposits $65 per month so you divide it and it will take 15.

$1800 ( wants to save up)
- $825 ( has saved up )
—————
$975 ( amount he has to save up )

$975 / $65 ( per month ) = 15 months