Question

At what rate of interest per annum willa sum of 62500 Rs earn a compound interest of 5100 Rs in one year ? The interest is to be compounded half yearly?

Answer 1

C.I.=A-P
5100=A-62500
A=62500+5100
=67600
A=P(1+R/100)^N
67600=62500(1+R/100)^1
67600/62500=1+R/100
678/625=1+R/100
678/625-1=R/100
53/625=R/100
R=100*53/625
=212/25%
=8(12/25)%

Answer 2

Answer: 5100= 62500. { ( 1+r/2×100)^2 - 1}

51/625 +1 ={1+r/200)^2

676/625 = {1+r/100)^2

26/25 =1+ r/200

1/25 =r/200

200/25 =r

r = 8%