He would have a monthly payment of $200
You multiply 48,000 by 5% and get 2400 then you multiply that by 5.
You get 12000.
To find his monthly payment you just Take 12 (number of months in a year) and times that by 5 (number of years) to get 60.
Then you take the 12000 and divide by 60 to get $200.