Peter borrowed $800 000 50 refit his fishing trawler. the loan requires monthly repayments over 15years. when he borrowed the money, the interest rate was 13.5% p.a. but 18months later the bank increased the rate to 15% p.a. The bank tells peter he can increase his monthly repayment (so as to pay off the loan by the originally agreed date) or he can extend the term loan (and keep making the same monthly repayment) Calculate the extra period added to the loan term if peter accepts the 2nd option.

I dont know how to find the answer for this.