Question

A sum of money amounts to 10000 after 5 years and 15000 after 8 years at the same rate of simple

mterest. Find the rate of interest per annum.​

Answer 1

Rate of interest = 99.99%

Explanation:

The computation of the rate of interest is shown below:

Given that

The amount after 5 years is 10,000

And, after 8 years it is 15,000

so for 3 years, it is

= 15000 - 10000

= 5000

Now the simple interest for one year

= 5000 ÷ 3

And, for five years, its is = 5000 ÷ 3 × 5

= 8333.33

Now the principal amount is

= 10,000 - 8333.33

= 1666.67

Now finally the rate of interest is

8333.33 = 1666.67 × Rate of interest × 5

Rate of interest = 99.99%