With the help of discount rate we present value of money. for example if we have 10% discount rate and we want to calculate present of 1000$ in two year. solution:- 1000*(1+0.10)^(-3) =751.315 10% =0.10 present value of 1000 in 4years? solution:- 1000*(1+0.10)^(-4) =683.01