Aptitude - Simple Interest - Discussion
Discussion Forum : Simple Interest - General Questions (Q.No. 9)
9.
A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?
Answer: Option
Explanation:
Let the original rate be R%. Then, new rate = (2R)%.
Note:
Here, original rate is for 1 year(s); the new rate is for only 4 months i.e. 
year(s).
 |
 |
725 x R x 1 |  |
+ | |
362.50 x 2R x 1 | |
= 33.50 |
| 100 | 100 x 3 |
(2175 + 725) R = 33.50 x 100 x 3
(2175 + 725) R = 10050
(2900)R = 10050
| R = |
10050 | = 3.46 |
| 2900 |
Original rate = 3.46%
Discussion:
97 comments Page 8 of 10.
Asif said:
1 decade ago
It should be:
725*r*8/(12*100) + 362.5*2r*4/(12*100) = 33.50.
R will be = 4.62%
725*r*8/(12*100) + 362.5*2r*4/(12*100) = 33.50.
R will be = 4.62%
Abhi said:
1 decade ago
Ya you should calculate for 8 months and 4 months.
Amith sourya said:
1 decade ago
The solution he given is wrong. Because for first case he took 8 months and for second month he took the remaining months i.e. 12-8 = 4. But he took in solution as 1 year.
Dolagobinda behera said:
1 decade ago
I agreed to @Tarun as the way he approached the question. I think the answer might be wrong as explained in the answer.
Kasinath said:
1 decade ago
Look @Maha :).
Let P=principal, I=Interest, R=Rate of Interest, T=time.
Let us consider two loans as Loan1 and Loan2.
In Loan 1: P1=725, R1=x, T1=1year.
In loan 2: P2=362.50 R2=2x, T2=After 8months it means(12-8)4MONTHS i.e., 4/12=1/3YEARS.
Given Interest I=33.50Rs of both Loan1 and Loan2.
Since I=PTR/100.
=>(P1*T1*R1/100)+(P2*T2*R2/100) = I ----EQUATION 1.
Now Insert the values a/c to equation 1 then you will get result.
Let P=principal, I=Interest, R=Rate of Interest, T=time.
Let us consider two loans as Loan1 and Loan2.
In Loan 1: P1=725, R1=x, T1=1year.
In loan 2: P2=362.50 R2=2x, T2=After 8months it means(12-8)4MONTHS i.e., 4/12=1/3YEARS.
Given Interest I=33.50Rs of both Loan1 and Loan2.
Since I=PTR/100.
=>(P1*T1*R1/100)+(P2*T2*R2/100) = I ----EQUATION 1.
Now Insert the values a/c to equation 1 then you will get result.
Mahalaksmi said:
1 decade ago
I am not understanding this problem please explain me clearly,
725*r*1/100+31.50*2r*1/100*3.
What does this 100*3 mean?
Please help me guys.
725*r*1/100+31.50*2r*1/100*3.
What does this 100*3 mean?
Please help me guys.
ANU said:
1 decade ago
This is how I did it.
[725*1*i/100]+[362.50*4/12*i/100] = 33.50.
7.25i+2.416i = 33.50.
9.66i = 33.50.
i = 33.50/9.66.
i = 3.46%.
Here I have taken i as rate of interest(R).
[725*1*i/100]+[362.50*4/12*i/100] = 33.50.
7.25i+2.416i = 33.50.
9.66i = 33.50.
i = 33.50/9.66.
i = 3.46%.
Here I have taken i as rate of interest(R).
Abdul rawoof khanday said:
1 decade ago
It is very important to understand question relate question with your daily life eg I deposited etc etc.
Sai krishna said:
1 decade ago
Please explain solution clearly with step by step process. How we got 1/3 as time in second case?
Syam prasad said:
1 decade ago
First interest only for a period of 8 months so time will become 8/12.
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