CH₃CH₂Br  +  AgCN  ------>  CH₃CH₂NC  +   AgBr

 

CH₃CH₂NC   +   H+  ------>   CH3CH2NH2  +   HCOOH

 

this is a simple reaction......  whats the doubt in the answer

 

AgCN is covalent in nature so the lone pair in nitrogen atom attacks the carbon atom so that Br goes out....... thus we get alkyl isocyanide as product which on hydrolysis gives corresponding amine and HCOOH

 

the mechanism of hydrolysis of isocyanide is given in the following link

 

it a google book  ..... see page 457 .........