A man borrows Rs. 21000 at 10% compound interest. How much he has to pay equally at the end of each year, to settle his loan in two years ?

We now that if Rs z is the amount to be paid by a person after n years then the present value of that Rs z is given as = $$\frac{z}{(1 + \frac{R}{100})^n}$$

where R is the Rate of Interest (Compounded Interest Rate)

So let assume that the amount of equal installment be Rs y

and hence we can say that if R = 10% per annum

and Principal Amount = Rs 21000

then present value of 1st installment + present value of 2nd installment = Rs 21000

$$\frac{z}{(1 + \frac{10}{100})^1}$$ +$$\frac{z}{(1 + \frac{10}{100})^2}$$ = 21000

$$\frac{2.1z}{(1.21)}$$ = 21000

z = Rs 12100