Aptitude - Simple Interest - Discussion

S.I for 1 year = 854 - 815 = 39.
S.I for 3 year = 39 * 3 = 117.
S.I for 4 year = 39 * 4 = 156.

Now,
Subtract the given amount of each simple interest amount
A = 815 - 117 = 698.
B = 854 - 156 = 698.
Both are same, so;
So, the answer is 698.

We can subtract it from 854 also but since we had calculated for 3 years we subtract it from 815 if you want to subtract from 854 do this.

4 x 39 = 156,
854 - 156 = 698.

Principal amt with SI for 3 yrs = 815 = total sum of money.
Principal amt with SI for 4 yrs = 854 = total sum of money.

So, to find SI for 1 yr = 854-815 = 39,
So, SI for 3 yrs = 39 *3 = 117 or Si for 4 yrs = 39*4 =156,


Total sum for 3yrs = P+SI..815 = P + 117..P= 815 -117 = 698.

Why have we taken out 39? I didn't understand anything Anyone, please explain me.

Simple interest for 1 year = 854 - 815 = 39.
Simple interest for 3 year = 39 * 3 = 117.
Simple interest for 4 year = 39 * 4 = 156.

Now,
Subtract the given amount of each simple interest amount
A = 815-117 = 698
B = 854-156 = 698
Both are same, so;
So, the answer is 698.
(15)

SI for 1 Year = 854 - 815=39,
SI for 3 year = 39 * 3 = 117,
And the Amount was = 854 - 117 = 698.

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

Simple interest for 1 year = 854 - 815 = 39.
Simple interest for 3 year = 39 * 3 = 117.
Simple interest for 4 year = 39 * 4 = 156.

Now,
Subtract the given amount of each simple interest amount
A = 815-117 = 698
B = 854-156 = 698
Both are same, so;
So, the answer is 698.

Thank you all for explaining the answer.

Thank you for explaining @Gayathri.