Aptitude - Simple Interest - Discussion

Hi,

In this question,for 8 months 750 with r%,remaining 362.5 with 2r% but he is doing for 1 year & 4 months,may be the answer is wrong ? what he explained.

In the question the SI for the second loan should be calculated for 4 months and not the whole year.

In question there is written After 8 months the rate is twice.

Then, why in the answer this is written the new rate (twice) is only for 4 months.

after 8 months principle should be 725+362.50 but in answer he was write only 362.50 how will it come?

And original rate only 8 months so time=8/12 years but he was write 1 year. how is?

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?

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%.

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.

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

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

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