Question

the simple interest on a certain sum of money at 4% per annum for 4 years is 19 rupees more than interest on the sum for 3 years at 5% per annum. find the sum of money?

Answer 1

We know S.I = P x R x T /100

 Given r = 4% t = 4 yrs

S.I = P x 4 x 4/100 = 0.16 P

A = P x (1 + r/100)^n

  here r = 5%, n = 3

   = P x (1 + 5/100)^3

   = P x (105/100)^3 or A = 1.157625 P

Now C.I = A - P = 1.157625 P - P

                   = 0.157625 P

It is given Rs 19 = 0.16 P - 0.157625 P

 So 0.002375 P = 19 or P = Rs 8,000