The total number of sp 2 hybridised carbon atoms in the major product P (a non-heterocyclic compound) of the following reaction is

Step-by-step solution

Lithium aluminium hydride is a strong reducing agent. It reduces cyanide to primary amine with no loss of carbon. Primary amine can undergo nucleophilic addition reaction with acetophenone to produce imine derivative. The carbon with one pi bond are sp 2 hybridised carbon. All the carbon in benzene ring are sp 2 hybridised. Hence, totally 28 sp 2 carbon are present in the molecule.