Question

the difference between SI and CI of a certain sum for 7 year at the rate of 2%pa is 180 . find the sum . please help its urgent

Answer 1

Let The Principal Be Rs x
For SI

P = x
R = 2%
T = 7years
I = PRT/100
  = x*2*7/100
  = 14x/100

For CI
P = x
R = 2%
T = 7 years
I = P(1 + r/100) raise to power of 7
  = x[(100 + 20/100]raise to power of 7
  = x(120/100)raise to power of 7
  = x(12/10)raise to power of 7  --------[Let not further divide]
  = x * 12 raise to power 7
    --------------------------------
       10 raise to power 7
  = 35831808x / 10000000

Difference of CI and SI = 180
Ofcorse CI is greater
35831808x  - 14x    = 180    [Taking LCM]
-----------         -----
10000000      100
35831808x - 1400000x = 180
--------------------------------
         10000000
34431808x = 1800000000
x = 1800000000/34431808
x = Rs 52.77

The Calculation became too complex so cant be sure whether it is right or not But I Tried My Best