a
\(C _{ x } HyOz +\left( x +\frac{ y }{4}-\frac{ z }{2}\right) O _{2} \rightarrow xCO _{2}+\frac{ y }{2} H _{2} O\)

\(0.3g\quad\quad\quad\quad\quad\quad\quad\quad0.2g\quad\quad\quad0.1g\)

\(\frac{ n _{ CO _{2}}}{ n _{ H _{2} O }}=\frac{ x }{ y / 2}=\frac{0.2 / 44}{.1 / 18}\)

\(\frac{2 x }{ y }=\frac{36}{44}=\frac{9}{11}\)

\(x =\frac{9 y }{22}\)

\(\frac{ n _{ C _{ x } H _{ y } O_{ z } }}{ nCO _{ 2 } }=\frac{1}{ x }\)

\(\frac{0.3 }{12 x + y +16 z } \times \frac{44}{0.2}=\frac{1}{ x }\)

\(66 x =12 x + y +16 z\)

\(54 x = y +16 z\)

\(\frac{54 \times 9 y }{22}- y =16 z\)

\(\frac{464 y }{22}=16 z\)

\(z =\frac{29 y }{22}\)

\(C _{ x } H _{ y } O _{z}= C _{ x } H _{ y } O _{z}\)

\(C _{\frac{9 y}{22}} H _{ y } O _{\frac{29 y}{22}}^{22}\)

\(C _{9} H _{22} O _{29}\)

\(\,\%\) of \(C =\frac{12 \times 9}{(12 \times 9+22+29 \times 16)} \times 100=\frac{108}{594} \times 100\)

\(18.18 \,\%\)