Aptitude - Simple Interest - Discussion

I agreed to @Tarun as the way he approached the question. I think the answer might be wrong as explained in the answer.

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.

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.

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).

It is very important to understand question relate question with your daily life eg I deposited etc etc.

Please explain solution clearly with step by step process. How we got 1/3 as time in second case?

First interest only for a period of 8 months so time will become 8/12.

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?

Principle of one year is Rs. 725 and next After 8 months it means a year end with 4 months (8+4=1 year). In this, principle of next 4 months after 8 months be Rs. 362.50.

S.I of 1 year + S.I of after 8 months = Total S.I.

Hey guys ,

Let the original rate be R%. Then, new rate = (2R)%.

1st,

Rs. 725 is lent in the beginning of the year(Whole year Time =1).

so S.I = 725*R*1/100.

2nd,

After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former.

find time,after 8 month means 12-8=4 month remaining.

4 month convert in year = 4/12= 1/3year.

Time = 1/3 year.

and then S.I = 362.50*2R*1/100*3.

Then add each,

(725*R*1/100)+(362.50*2R*1/100*3) = 33.50.

(2175 + 725) R = 33.50 x 100 x 3.

(2175 + 725) R = 10050.

(2900)R = 10050.

R = 10050/2900 = 3.46.

Original rate = 3.46%.

It is not specified in the the question.

1. What is original rate of interest whether it is rate of all the money involved or it is only for money other than 362.50 rupees?