SOLUTION
[tex]\begin{gathered} The\text{ three people can be selected for the 8 seats using the combination } \\ in\text{ the form of } \\ ^8C_3 \end{gathered}[/tex][tex]\begin{gathered} ^8C_3\text{ = }\frac{8!}{(8-3)!3!} \\ \\ =\text{ }\frac{8\times7\times6\times5!}{5!\times3\times2} \\ \\ =\frac{336}{6} \\ \\ =\text{ 56 ways } \end{gathered}[/tex]