Question

What is the rate of compound interest that
causes Rs. 720 to earn Rs. 164.90 in 7 years?
​

Answer 1

Answer:

9000

Step-by-step explanation:

Interest for 1 year=Rs.720

Interest for 2 years=Rs.1497.60

∴ Interest for 2nd year=1497.60−720=Rs.777.60

As the interst is not same for two years, it is compund interest not simple interest.

Difference between C.I of two successive years=777.60−720=Rs.57.60

∴Rate of interest=

720×1

57.60×100

=8%

Let the sum be Rs.100

∴Interest on it for 1st year=8% of 100=

100

8

×100=Rs.8

If the interest for one year is Rs 8 then sum=Rs.100

If the interest for one year is 720 then sum=

8 than sum 100

8/100×720=Rs.9000