Need help with number three and all the parts that go with it thank you !

A combustion reaction takes place in the presence of oxygen gas. The combustion of an alkane produces carbon dioxide and water.
[tex]\begin{gathered} a)\text{ }2C_4H_{10}+13O_2\rightarrow8CO_2+10H_2O \\ b)\text{ }C_6H_{12}+9O_2\rightarrow6CO_2+6H_2O \end{gathered}[/tex]