Answer :
[tex]_{8} C_2 \\ \\ \frac{8!}{(8-2)!2!} \\ \\ \frac{8!}{6!2!} \\ \\ \frac{8*7*6*5*4*3*2*1}{6*5*4*3*2*1*2*1} \\ \\ \frac{8*7}{2*1} \\ \\ \frac{56}{2} \\ \\ 28 [/tex]
28 different teams
28 different teams