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 :

The remainder when 3²⁰²² is divided by 5 is :

The surface area of a balloon of spherical shape being inflated, increases at a constant rate. If initially, the radius of balloon is 3 units and after 5 seconds, it becomes 7 units, then its radius after 9 seconds is :