Aptitude - Simple Interest - Discussion

12. 

What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years?

[A]. 1 : 3
[B]. 1 : 4
[C]. 2 : 3
[D]. Data inadequate
[E]. None of these

Answer: Option C

Explanation:

Let the principal be P and rate of interest be R%.

Required ratio =
P x R x 6
100
= 6PR = 6 = 2 : 3.
P x R x 9
100
9PR 9

Video Explanation: https://youtu.be/GaaEDwTWc6w


Insaan said: (Mar 7, 2011)  
Simple way is

S.I is directly proportional to T, we can write

S1/S2 = T1/T2
= 2/3

Angle said: (May 18, 2011)  
Lets interest of certain amount is X.

so after 6 year is 6X and after 9 year is 9X.

For Ratio ==> 6X : 9X = 2:3

Anchal said: (Jun 16, 2011)  
Dear Insaan and Angle, we know we got same Ans from your's method. But there is no any logic. Thats why we have to needed the interest formula. And through the interest formula we can also find out ratio even in different rate of interest.

Ashik said: (Jul 30, 2011)  
Assume the amount=100

If interest is 10% ,amount of interest is 10 rs.

then the amount of interest for 6 yrs = 6*10 rs = 60 rs

and for 9 yrs amt of interest for 9 years = 9*10 rs = 90rs

For ratio, s1/s2 = 60/90 = 2/3.

Prasant said: (Apr 4, 2012)  
Is it clear from the question that the pricipal amount is same in both the cases?

Manoj said: (Sep 24, 2014)  
But in question it is not mentioned that principal is same.

Prem said: (Jul 28, 2016)  
Yes, Agree with Manoj.

Indramani said: (Jun 17, 2017)  
Answer should be data inadequate. Suppose principal is 100 and we take 5% interest, then after 6yrs it will be 130 and after 9 years it will be 145. Solving this gives 26/29 which is not equal to 2/3.

Ujju said: (Jan 20, 2019)  
P and R is constant.

Then ratio = t1/t2.

Amrik Singh said: (Jun 3, 2019)  
3:2 is correct. Not 2:3 because rate of interest is inversly proportional to time.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.