Aptitude - Simple Interest - Discussion

Hi Friends!
Principle = the amt u borrowed
Interest = the small additional amt u pay for the amt u
borrowed

First let me explain u d question
In the question,
A sum of money at simple interest amounts to Rs. 815 in 3 years means the Principle amt together wit the interest paid for 3 yrs is Rs. 815 and similarly Principle amt together wit the interest paid for 4 yrs is Rs. 854

Therefore, if we subtract (854-815) we get the simple interest for 1 year as Rs. 39

Then, we calculate simple interest for 3 yrs as (39*3)= 117

Next step, we subtract (815 - 117) to get Principle amt for a yr as Rs. 698

Brief explanation for last step:

815 = Principle amt + int for 3 yrs ......equation 1
117 = int for 3 yrs ......equation 2

now subtract both equations, we get the principle amt

I hope tat this explanation will be helpful to u

S.I=PTR/100

S.Ib = PNR/100

What is formula of simpe interest ?

I like this type of solutions thank you

I think this answer also

1year 854-815=39

3years 39*4=156

854-156=698

PTR/100 = 815
P*3*R/100 = 815
R/100=854- 815
p * 3 * 39 = 815
P * 117 = 815
p = 815-117 = 698

To get a si of one year or it might be two years if it is two year we have to divide it by two si=3yrs -2yrs willl give u one year si why should we have to go to risk.

Hai friends,

Principle is the amount borrowed. Here, explain about SI of 3 years and 4 years. Assume P is the principal then, P+854 for 4 years and p+815 for 3yrs.

So here it is necessary to find the SI of one year and subtract it from the 3 year or 4 year.

That is, (815-117) = 698 and 854-156=698.

Thank you. This is explanation is very helpful for me.

@Lavanya and kanna

To get 1 year difference we have to subtract
4year amount-3year amount
this difference amount is the 1 year simple interest..
that's why..
Rs. (854 - 815) = Rs. 39
39 is 1year S.I.

hope it helps you..