Aptitude - Simple Interest - Discussion

The Answer is 35.

Equation One = 7*P*R/100=1750
to be found (7*P*R+2)/100 = ?
we can rewrite as (7*P*R)100 + 2/100 = ?
and then 1750 + 2/100 = 35.

As per data specified p and yr are constant only rates changes.
Moreover, SI is directly proportional.
So, I think the answer would be 35.

I think the answer should be 35. I am not getting why they are saying data inadequate.

Old interest=(P*R*7)/100= 1750.

New interest= [P*R*7*(102/100)]/100.
=[(P*R*7)/100]*[102*100].
=1750*(102/100),
=1785.

So, the answer is = New Interest- Old interest = 1785 - 1750 = 35.

Here in the first case;

P * 7 * R/100 = 1750 -----> (1)
And in the second case interest is increased by 2%( Rate of interest).

P*7*(R+2)/100=? -------> (2)

HERE THE Rate of Interest is R+2 because the 100 in the demo is for the Rate of Interest Calculation i.e., R/100 is R%.

So, by the two equations, we get 3 unknown values. But to solve 3 unknown values we need 3 equations. hence there is no solution for this question unless one of the 3 unknown values is given.

1750 = PR7/100.

=>PR = 25000-----(1).

Again,
SI = (P*102/100*R*7) / 100.

=>PR = (100*100*SI) / 7*102------(2).

By equating (1) and (2).

SI = 1785.

So ans is 1785-1750 = 35.

Answer (C) Let us assume the principal amount and interest rate is 2500 and 10%. In that, the rate increases by 2%, meaning the interest rate is 12%.

From that, we must calculate using the Simple interest formula PNR/100. New SI after 7 years is 2100 and (2100 -1750) = 350 rs.

1750 divided by 7 give Interest for one year ie, Rs 250.

Here, 2% of 250 is 5.
So if the interest is increased by 2% then the Interest for one year will 255.
So for 7 years 1785.
Thus the difference will be Rs 35.

Can we consider the amount as 1000 and calculate the interest. As for one year S.I is 250. So we get the rate of interest as 25. And if we add two percent to it and get S.I it will be 270. 270x7 will give you 1890. So 1890-1750 should give you 140. Then Why it can't be determined?

2% increase in interest- here interest is simple interest because we never call rate of interest as interest.

So answer is 2% of interest= (2% of 1750) =35 given, interest=1750.

The answer should be 35.

Given:
p*r*7/100 = 1750.

According to question;

new rate = r+2%of r.
new rate = r+0.02*r.
new rate = 1.02*r.
Hence new SI = p*1.02*r*7/100,
new Si = 1.02*p*r*7/100,
new Si = 1.02*1750,
= 1785.

Difference = 1785-1750 = 35.