Engineering Economy with Calculator Techniques

Engineering
Economy

, -
SIMPLE INTEREST -




↳ basis of interest is always the initial amount

Solh : -
69


O 31 100
° i 2 3 n


period
F =p ( It rn ) l l l 7
# I > n, * assume
ordinary simple

#/
. . .
,
I
t i t ! ( year month ,
etc) N interest ,
unless specified
p
,

l l
F D where u
I
=

Prn
l
-
l :
' '
= A assume annual interest
* eco .o , )
l
l
f
v

P
I l l
l P 0.97 F
-
- rate ,
unless specified
0.03ft
D
-




l
-




Pt Pr l l

TI l l
Ptprcz)
tr
l l
net interest :
I
'
Ptprl 's
I T
1
, I = -


I =
Prn
+


¥0 )
Ptprn F
0.03¥ : 0.97 #4) (
-
-




r 0.1614 16.14%
-
-
or




* 2 Types of simple Interest *


•

Ordinary
↳ assumes that there are 30 days ) month
360 called the
or
days in a
year ,

"
banker's rule
"
Solh :

• Exact I
'
-
-
I -

T

↳ assumes the exact days in a
year 890.36 i
I
-

0.2015

wk is 365 ( regular) and 366 ( leap year) I
-
-


1112.95

SAMPLE PROBLEMS :

I =
Prn


1112.95--110000 (r )(}÷o)
r :
0.1175 I 11.75%
Solh:

From May 1,2002 to
May 1,2005 = 3 (360)
From
May I , 2005 to Aug .
1,2005 : 90

1170
days
I : Prn


317600 )
'
=
250006.08)(
I 6,500
-
-




Solh :

May I,
20021365
May 1,2003
May 1,20041366
May 1,20051365
May 131 )



August 1,2005
! Junko )
July ( 31 )

1188
days

I -
-
Prn

8386¥ )
"
'
25.0001000)(
I :
6,504.11