Chemical Bonding And Molecular Structure

The bond dissociation energy of $ X_{2}, Y_{2} $ and $ X Y $ are in the ratio of $ 1: 0.5: 1 . \Delta H $ for the formation of $ X Y $ is $ -200 \mathrm{~kJ} / \mathrm{mol} $. The bond dissociation energy of $ X_{2} $ will be