Question

find the time, in which 64000 becomes ₹68921 if the rate of interest is 5% per half yearly?​

Answer 1

principle = 64000

amount = 68921

interest = 68921-64000=4921

rate of interest = 5% per half year

A=P(1 + r/2/100)^2n

68921=64000(1+2.5/100)^2n

68921=64000{(100+2.5)/100}^2n

1.07={(100+2.5)/100}^2n

1.07={(102.5)/100}^2n

1.07={(1.025)^2n

1.07=1.05^n

n=3/2

therefor time required is 1 year and 6 months