ANSWER
465 different ways
STEP BY STEP EXPLANATION
Step 1: Using Combination
[tex]C(n,r)\text{ = }\frac{n!}{r!(n-r)!}[/tex]Step 2: from the question, n = 31 and r = 2
[tex]\begin{gathered} C(31,\text{ 2) = }\frac{31!}{2!(31-2)!} \\ \text{ = }\frac{31\ast30\ast29!}{2!(29)!} \\ \text{ = }465 \end{gathered}[/tex]Hence, you can select co-captains from the team in 465 different ways