Two liquids X and Y form an ideal solution. At 300K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mm Hg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure of the solution increases by 10 mm Hg. Vapour pressure (in mm Hg) of X and Y in their pure states will be, respectively :

Arrange the carbanions, $${(C{H_3})_3}\overline C $$, $$\overline C C{l_3}$$ , $${(C{H_3})_2}\overline C H$$, $${C_6}{H_5}\overline C H{}_2$$ in order of their decreasing stability :

The IUPAC name of neopentane is

The alkene that exhibits geometrical isomerism is :