Question

A certain sum of money amounts to 3 7378 in 2 years and 3 8092 in 3 years. Find the
rate of interest and the principal.​

Answer 1

Answer:

This is a simple quadratic equation involving simple interest. Read the question loudly and you will understand that there are 2 scenarios given which will help us find the answer.

Now, formula for simple interest (SI) = (P*R*T)/100.

where,

P = Principle,

R = Rate of interest, and

T = Time in years.

If we have to find the total money after certain years, the principle has to be added to the interest earned.

So, Sum = P + SI

Let's go to the question now.

Case 1 : Rs. 1008 in 2 years.

So, 1008 = P + P*R*2/100

Case 2 : Rs. 1164 in 7/2 years

So, 1164 = P + P*R*7/200

Solving these 2 equations, we get the values as

P= 800

R = 13

Hence to answer your question - Rs. 800 if invested at 13% p.a. Simple interest will give Rs. 1008 in 2 years and Rs.1164 in 7/2 years.

Hope it helps.