Answer:
loan balance after 12 years = $185409.8
Explanation:
Loan principal = $200000
interest = 10% of principal
amount paid yearly  = $21215.85
For 1st year
principal for the first year = $200000
required interest to be paid = 10% of 200000 = $20000
amount paid = $21215.85
Loan Balance after first year = (principal for first year) - (amount paid - 10% of principal ) = $198,784.15
For 2nd year
principal for the 2nd year = Loan balance after first year = $198,784.15
loan balance after 2nd year = 198784.15 - ( 21215.85 - 10% of 198784.15)
= $197568.30
same applies for the different years until the 12th year
using this formula :
Loan Balance after Nth year = [ Loan balance after (n-1) year - ( amount paid - 10% of loan balance after (n-1) year ) ]