If after two years a sum becomes ₹4000 and after four years it becomes ₹6000 at the same rate of compound interest (compounded annually), then what is the sum?

₹2666.66

The Formula that we used here is -

Amount = P$(1 \;+\; \frac{R}{100})^t$

4000 = P [ 1 + \(\frac{R}{100}\) ]²        -----(1)

& 6000 = P [ 1 + \(\frac{R}{100}\) ]4     ------(2)

Divide equation 2 by equation 1.

\(\frac{3}{2}\) = [ 1 + \(\frac{R}{100}\) ]²

By putting in equation 1 .

4000 = P × \(\frac{3}{2}\)

P = 2666.66