: , .
:
Ø (n)
Ø (PV),
Ø (FV),
Ø (r)
:
F n (. number of periods) , . , ( ) .
, , , , , . . , , . . -.
m , n ,
N = n m (1‑1)
F PV (. present value) , , ;
F FV (. future value) , .. ;
F I (. interest[2] money), "", .
I= FV-PV (1‑2)
, , , . () . - :
F r [3] ( rate of interest ), , , , . , .
r = I/PV = (FV PV) / PV (1‑3)
(r) , , .. .
(FV PV) PV, FV, ,
|
|
d = (FV PV) / FV, (1‑4)
(. discount rate), ( )[4].
, , (d) , .
[5]:
ð :
r = (FV - PV) / PV (1‑5)
ð :
d = (FV - PV) / FV (1‑6)
(I=FV-PV) . , , (FV) .
(FV - PV) = d*FV = r*PV (1‑7)
r = d*(Fv/PV) (1‑8)
d = r*(PV/FV) (1‑9)
1‑1
100 ., 120 .
(r) (d) , , n =1.
PV = 100 ., FV = 120 ., I =(FV PV) = (120 100) = 20 ., r = 20/100 = 20%, d = 20/120 = 16.67%.
1‑2
.
100 . (PV) 1 (n=1).
, =20%?
.
2-5 2-6 FV :
FV = PV* (1+r) (1‑10)
FV = PV/(1-d) (1‑11)
r =d =0.2:
FV =100 .*(1+0.2) =120.
FV=100 ./(1-0.2) = 125 .