Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Order of acidic nature of the following compounds is A > B > C.

Reason R : Fluoro is a stronger electron withdrawing group than Chloro group.

In the light of the above statements, choose the correct answer from the options given below:

A(g) $$\to$$ 2B(g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be _________ mm Hg. (Nearest integer)

$$0.400 \mathrm{~g}$$ of an organic compound $$(\mathrm{X})$$ gave $$0.376 \mathrm{~g}$$ of $$\mathrm{AgBr}$$ in Carius method for estimation of bromine. $$\%$$ of bromine in the compound $$(\mathrm{X})$$ is ___________.

(Given: Molar mass $$\mathrm{AgBr=188~g~mol^{-1}}$$

$$\mathrm{Br}=80 \mathrm{~g} \mathrm{~mol}^{-1}$$)

See the following chemical reaction:

$$\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{XH}^{+}+6 \mathrm{~F}_{e}^{2+} \rightarrow \mathrm{YCr}^{3+}+6 \mathrm{~F}_{e}^{3+}+\mathrm{Z} \mathrm{H}_{2} \mathrm{O}$$

The sum of $$\mathrm{X}, \mathrm{Y}$$ and $$\mathrm{Z}$$ is ___________