Question

Question #8b177

Answer 1

24

Explanation:

Let the sum (P) be x. It becomes double means 2x in 8 (T) years.

It means Interest (I) = 2x - x = x. we have to fine the rate of interest

(R) from here.

We know, I = PRT/100

`rArr x = (x. R. 8 )/100`

`rArr R = 100/8`

Again, Sum (P) = x, sum + interest = 4x. Interest (I) = 4x - x = 3x

Rate of interest (R) = 100/8 and we have to find no. of years (T)

We know I = PRT/100

`rArr 3x = ( x. 100/8. T)/100`

`rArr 100/8. T = 300`

`rArr T = 300 xx 8/100 = 24`