Question

(3 A sum of money doubles itself in 6 years. In how many years, it becomes 5 times? ​

Answer 1

In 24 years.

Explanation:

Let the sum of money be 100 which amounts to 200 ( doubles itself ) in 6 years time. Interest on 100rs. Is 100. Putting the following in simple interest formula. You get :

`100=(100* R* 6)/(100)\\\\R=(100)/(6)`

Now when 100 will become 5 times i.e 500 the interest will be 400rs.

Putting in simple interest formula:

`400=((100* 100)/(6T))/(100)\\\\T=(2400)/(100)\\\\=24\ yrs`

So, in 24 years, it will become 5 times.