Question

a sum was invested for 3 yrs at a certain rate of simple interest. if it had been invested at 2% more annual rate of interest, then Rs 114 more would have been obtained what is the sum?

Answer 1

Answer:

The sum is Rs. 1900

Step-by-step explanation:

Let the given sum is Rs. P, rate of interest = r% p.a., time = t years and interest = Rs. I

Then the relation among P, r, t, I is

I = Ptr/100

Given, t = 3 years

Case 1.

When the rate of interest is r%,

I = (P * 3 * r)/100

or, I = 3Pr/100 ..... (1)

Case 2.

When the rate of interest is 2% more, i.e., (r + 2)%,

I' = {P * 3 * (r + 2)}/100

or, I' = 3P (r + 2)/100 ..... (2)

By the given condition,

I' - I = Rs. 114

or, 3P (r + 2)/100 - 3Pr/100 = 114

or, (3Pr + 6P - 3Pr)/100 = 114

or, 6P = 11400

or, P = 1900

Therefore the required sum is Rs. 1900