Find the principal, if the compound interest compounded annually at the rate of 10% perannum for three years is Rs 331

To find the principal when the compound interest, rate of interest, and time period are given, we can use the formula for compound interest which is:

A = P (1 + r/n)^(nt)

Where: A = the amount of money accumulated after n years, including interest. P = principal amount (the initial amount of money) r = annual interest rate (in decimal) n = number of times that interest is compounded per year t = time the money is invested for in years

In this case, we know that A (the total amount after 3 years) is the sum of the principal and the compound interest. So, we can write it as:

A = P + CI

We can substitute the given values into the formula:

331 = P + P(1 + 0.10/1)^(1*3)

Solving the equation will give us the value of P (the principal).

Let's simplify the equation:

331 = P + P(1.10)^3 331 = P + P(1.331) 331 = 2.331P

Now, solve for P:

P = 331 / 2.331 P = Rs 142.07

So, the principal is approximately Rs 142.07.