We have received a $100\mathrm{.}000$ loan over a period of $12$ years using

the American system and the following conditions:

$$ EAIR $=15\%$

$$ Six monthly payments

At the end of the fourth year, along with the corresponding

payment, $20,000$ is also paid with the objective of reducing the

debt. At this point, it is decided to repay the outstanding amount

by means of annual constant payments, maintaining the duration

of the loan and the interest rate. Calculate the amount of these

payments.