Bunuel wrote:
manalq8 wrote:
In how many different ways can a group of 8 people be divided into 4 teams of 2 people each?
90
105
168
420
2520
90
105
168
420
2520
\(\frac{C^2_8*C^2_6*C^2_4*C^2_2}{4!}=105\) , we are dividing by 4! (factorial of the # of teams) as the order of the teams does not matter. If 8 people are - 1, 2, 3, 4, 5, 6, 7, 8, then (1,2)(3,4)(5,6)(7,8) would be the same 4 teams as (5,6)(7,8)(1,2)(3,4), as we don't have team #1, team #2...
You can think about this in another way.
For the first person we can
...






