Which of the following is the strongest acid?

In the reaction $CH_3Br + KCN_{(alc)} \to X \xrightarrow[Na + C_2H_5OH]{reduction} Y$,identify $Y$.

When a concentrated solution of sulphanilic acid and $1-$naphthylamine is treated with nitrous acid $(273 \ K)$ and acidified with acetic acid,the mass $(g)$ of $0.1 \ mole$ of product formed is : (Given molar mass in $g \ mol^{-1} H: 1, C: 12, N: 14, O: 16, S: 32$)

Arrange the following compounds in increasing order of their basicity:
$CH_3NH_2, (CH_3)_2NH, C_6H_5NH_2, (CH_3)_3N$

Given below are two statements:
Statement-$I$: In Hofmann degradation reaction,the migration of only an alkyl group takes place from carbonyl carbon of the amide to the nitrogen atom.
Statement-$II$: The group is migrated in Hofmann degradation reaction to an electron-deficient nitrogen atom.
In the light of the above statements,choose the most appropriate answer from the options given below:

What is the correct order of basic strength for $NH_3$,$CH_3NH_2$,and $(CH_3)_2NH$?