A has 50 coins of 10 paise denominations. While B has 10 coins of 50 paise denominations. C has 20 coins of 25 paise denominations while D has 25 coins of 20 paise denominations. The average number of paise per person is :

$$\eqalign{ & \frac{{\left}}{4} \cr & = 500\,{\text{paise}} \cr} $$