A 0.166 g sample of an organic compound was digested with conc. H₂SO₄ and then distilled with NaOH. The ammonia gas evolved was passed through 50.0 mL of 0.5 N H₂SO₄. The used acid required 30.0 mL of 0.25 N NaOH for complete neutralization. The mass percentage of nitrogen in the organic compound is ____________.

Number of electrophilic centres in the given compound is _______________.

The major product 'A' of the following given reaction has _____________ sp² hybridized carbon atoms.

Let $$A = \{ z \in C:1 \le |z - (1 + i)| \le 2\} $$

and $$B = \{ z \in A:|z - (1 - i)| = 1\} $$. Then, B :