In How much time? If
A certain sum of money doubles itself in 5 years at S.I. in how many years it becomes 7 times itself?
- 10 years
- 20 years
- 30 years
- 32 years
Answer: (c) 30 years
Explanation:-
Let the principal is X
According to question, money doubles itself in 5 years
then S I = 2X – X = X
Now, we can find the rate
X = (X x R x 5)/100
R = 20%
Again X becomes 7 times itself, then S I = 7X – X = 6X
6X = (X x 20 x T)/100
T = 30 years
Hence, in 30 years it becomes 7 times itself.
