Identify product '$$\mathrm{B}$$' in following reaction.

$$\mathrm{CH}_3 \mathrm{Br}+\mathrm{AgNO}_2 \longrightarrow \mathrm{A} \xrightarrow{\mathrm{Sn} / \mathrm{HCl}} \mathrm{B}$$

A balloon contains $$2.27 \mathrm{~L}$$ air and has a pressure of $$1.013 \times 10^5 \mathrm{~Nm}^{-2}$$. The balloon rises to a certain height and expands to volume of $$4540 \mathrm{~mL}$$. What is the final pressure of air in balloon?

If A(3, 2, $$-$$1), B($$-$$2, 2, $$-$$3) and D($$-$$2, 5, $$-$$4) are the vertices of a parallelogram, then the area of the parallelogram is

If $$\hat{a}$$ is a unit vector such that $$(\bar{x}-\hat{a}) \cdot(\bar{x}+\hat{a})=8$$, then $$|\bar{x}|=$$