A sum of money becomes Rs.17820 after 4 years and Rs.23760 after 6 years on compound interest when the interest is compounded annually. What is the half of the sum (in nearest a Rs.).

5012

             4 years      :       6 years

Sum :     17820       :        23760

Sum :         3           :           4

So initial amount = 17820 × \(\frac{3}{4}\) × \(\frac{3}{4}\)

Half of the initial amount: = 17820 × \(\frac{3}{4}\) × \(\frac{3}{4}\) × \(\frac{1}{2}\) 

                                          = 5011.8 = ∼ 5012