The element whose percentage composition in an organic compound can be determined by the Carius method is

In $Duma's$ method of estimation of nitrogen,$0.35 \ g$ of an organic compound gave $55 \ mL$ of nitrogen collected at $300 \ K$ temperature and $715 \ mm$ pressure. The percentage of nitrogen in the compound is (aqueous tension at $300 \ K = 15 \ mm$). (in $.45$)

The number of moles of $CuO$ that will be utilized in the Dumas method for the estimation of nitrogen in a sample of $57.5 \ g$ of $N,N$-dimethylaminopentane is $..... \times 10^{-2}$. (Nearest integer)

Given below are two statements :
Statement $I$ : Kjeldahl method is applicable to estimate nitrogen in pyridine.
Statement $II$ : The nitrogen present in pyridine can easily be converted into ammonium sulphate in Kjeldahl method.
In the light of the above statements,choose the correct answer from the options given below.

Which compounds are taken in the Kjeldahl's flask for the estimation of nitrogen?

How is the percentage of oxygen determined in the quantitative estimation of organic compounds?