Identify $X$ in the following sequence of reaction:
$C_6H_5-Cl$ $\xrightarrow[CuCN]{KCN} P$ $\xrightarrow{LiAlH_4} Q$ $\xrightarrow{HNO_2} X$

Three houses are available in a locality. Three persons apply for the houses. Each applies for one house without consulting others. The probability that all the three apply for the same house is

Who among the following is known as the 'Father of Taxonomy'?

The height of the cone of maximum volume inscribed in a sphere of radius $R$ is

Element having highest $I.P.$ value is

$1.00 \ g$ of a non-electrolyte solute (molar mass $250 \ g \ mol^{-1}$) is dissolved in $51.2 \ g$ of benzene. If the freezing point depression constant of benzene is $5.12 \ K \ kg \ mol^{-1}$,then the freezing point of benzene decreases by ...... $K$.