Aptitude - Simple Interest - Discussion

Can't the answer be Rs. 255.

Since Rs. 1750 interest earned in 7 years means Rs. 250 interest earned in 1 year.

Now (P*R*T)/100 = SI.

For 1 year, it will be (P*R*1)100 = 250.

i.e P*R = 25000.

Now again, when rate increased by 2%.

For 1 year, it will be (P*102R/100*1)/100 = ?

i.e (P*R*102/100)100 = ?

Putting P*R = 25000 from above.

(25000*102/100)100 gives Rs. 255.

Please correct me if I'm wrong but this is what I think.

@Sparsh.

255-250 = 5.
5*7 years = 35.

That's the answer. Increase in simple interest.

i = pxrxt/100.

pxr = (ix100)/t = 25000.

Now we have constant value of pxr.

Now if we are saying that the new rate is 2% more.

Than new rate = r+(2% of r) = r+(2r/100) = r(102/100) = 1.02r.

When new are is 1.02r.

The i = px(new-r)xt/100.

i = px 1.02r x t/100 = (pxr x 1.02 x 7)/100.

We have pxr = 25000 (calculated in first step).

So i = 25000x1.02x7/100 = 1785.

So gain in interest = 1785-1750 = 35.

As rate of interest is 2% for 7 years it is 14%.

That's why there is increase in interest that is 1750(14%increase) = 1995.

The extra amount would be 1995-1750 = 245.

For all those who are solving the problem using "2% of R" , R being the Rate of Interest, its not given so in the problem. It's given as 2% more..not 2% of R.

I had been trying to solve using this method and was getting answer as 350.

Then I realized the mistake and I am currently doing the problem as "R+2%".
Now I am not getting the answer since R is not known, as well as P(Principal).

In simple words..do the problem by "R+2%" not by "1.02R"
So the answer is D) Cannot be determined.

Please anyone confirm that what is the correct answer or data is not sufficient. As Indiabix says answer "Cannot be determined".

I have seen similar questions in Kiran's Mathematic book and Paramount airthematic book.

A 2% increase in rate means.

If the rate was 5% per annum earlier then it is 7% now.

So I guess IndiaBix is right and hence no solution exist to this problem.

They are asking about the amount of increase. So 35 is the answer.

I think the answer will be Rs. 35 because if we take the ratio of the two simple interests then the principal, time and rate of interest cancelled out. In RHS it is 7/7.14. In LHS it is 1750/ (SI2).

After solving the answer will be Rs. 35.

I think, here rate of interest is obviously in percent, i.e. increased by 2% simply means, r% will become (r+2)%, thus we can't get 35 as an answer. We need to know rate of interest for it which can't be evaluated due to insufficient data. Thus answer will be 'D'.