1. Given data

   • Mass of organic compound $= 500\text{ mg}$
   • Mass of $\mathrm{CO_2}$ produced $= 220\text{ mg}$

2. Find mass of carbon present in $\mathrm{CO_2}$

   In $\mathrm{CO_2}$, $\text{Molar mass of } \mathrm{CO_2} = 12 + 2\times 16 = 44$

   Out of $44$ g of $\mathrm{CO_2}$, carbon contributes $12$ g.

   Therefore, mass of carbon in $220\text{ mg}$ of $\mathrm{CO_2}$ is $\frac{12}{44}\times 220 = 60\text{ mg}$

3. Find percentage of carbon in the compound

   The $500\text{ mg}$ sample contains $60\text{ mg}$ carbon.

   So, $\%\text{ of carbon} = \frac{60}{500}\times 100 = 12\%$

4. Nearest integer $12$

Hence, the percentage composition of carbon in the compound is $12\%$.