The figure shows experimental set up of a meter bridge. When the two unknown resistances X and Y are inserted, the null point D is obtained 40 cm from the end A. When a resistance of `10 Omega` is connected in series with X, the null point shifts by 10 cm. Find the position of the null point when the `10 Omega` resistance is instead connected in series with resistance 'Y'. Determine the value of the resistance X and Y