At compound interest, if a certain sum of money doubles in n years
Posted on 28-04-2023
Ques - At compound interest, if a certain sum of money doubles in n years, then the amount will be four fold in :
(a) n2 years
(b) 2n2 years
(c) 2n years
(d) 4n years
Solution -
Given,
A = 2P
A = P (1 + (r/100))n
2P = P (1 + (r/100))n
2 = (1 + (r/100))n
Then,
The amount will be four fold
4 = (2)2 = [(1 + (r/100))n]2
4 = (2)2 = [(1 + (r/100))2n]
Here,
Time period = 2n [(am) n = am.n]
Therefore,
The amount will be four fold in 2n years.
Hence,
The correct answer is option (c) 2n years.
Thank You