A certain sum of money triples itself in 5 years at simple intere
| A certain sum of money triples itself in 5 years at simple interest. In how many years it will be five times?
A. 5
B. 8
C. 10
D. 15
Please scroll down to see the correct answer and solution guide.
Right Answer is: C
SOLUTION
Given: A certain sum of money triples itself in 5 years at simple interest.
Let the initial amount be P
Amount after 5 years = 3P
SI = Amount - Principal = 3P - P = 2P
∴ SI in 5 years = 2P
We know that, SI = Prt/100
Or, 2P = Pr × (5/100)
⇒ r = 40%
Let it become 5 times in t years, then
SI in time t = 4P
Or, 4P = P × 40 × t/100
⇒ t = 10 years
Note: Amount is 3 times of Principal in 5 years which means SI is two times of Principal in 5 years.
Amount to be 5 times of Principal, we have to make SI 4 times of principal. So, it will take 10 years.
Hence, option C is the correct answer.