he compound interest on rs.30000 at 3.5% per annum is Rs.4347. The period is:

The problem is about calculating the time period for a given compound interest. The formula for compound interest is:

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

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

Given in the problem: P = Rs. 30000 A = P + compound interest = 30000 + 4347 = Rs. 34347 r = 3.5% per annum = 0.035 (in decimal) n = 1 (assuming the interest is compounded annually)

We need to find 't'.

Substituting the given values in the formula:

34347 = 30000 (1 + 0.035/1)^(1*t)

Divide both sides by 30000:

1.1449 = (1.035)^t

Take the natural logarithm (ln) on both sides:

ln(1.1449) = t * ln(1.035)

Now, divide both sides by ln(1.035) to solve for t:

t = ln(1.1449) / ln(1.035)

Use a calculator to find the values of ln(1.1449) and ln(1.035), and then divide the first by the second to get the value of t.

Please note that the exact value of 't' will depend on the accuracy of the calculator used.