If $$\sqrt x $$  - $$\sqrt y $$  = 1, $$\sqrt x $$  + $$\sqrt y $$  = 17, then $$\sqrt {xy} $$  = ?

Solution (By Examveda Team)

$$\eqalign{ & \sqrt x - \sqrt y = 1\,......(i) \cr & \sqrt x + \sqrt y = 17\,.....(ii) \cr & {\text{From equation (i) and (ii)}} \cr & \sqrt x = 9,\sqrt y = 8 \cr & {\text{So, }}\sqrt {xy} = 9 \times 8 = 72 \cr} $$