this is simple .. apply formula...
Po -P / Po = m2/m1
The vapour pressure of water at 20°C is 17.5 mm Hg. If 18 g of glucose (C6H12O6) is added to 178.2 g of water at 20°C, the
vapour pressure of the resulting solution will be
(1) 16.500 mm Hg (2) 17.325 mm Hg (3) 17.675 mm Hg (4) 15.750 mm Hg