Answer:
28 groups of 2.
Explanation:
That would be the number of possible combinations of 2 out of 8 , written as 8C2.
8C2 = 8! / (8-2)! 2!
A quick way of working this out is 8*7 / 2*1 . The above formula simplifies to this. Note the numerator starts with 8 then you multiply by 7 (8-1). The number of values in the numerator depends on the combination value ( in this case it is 2). The denominator here is 2*1.
So the answer is 8*7 / 2*1 = 28 ways.
Other examples of combinations:
7C4 = 7*5*4*3 / 4*3*2*1
10C3 = 10*9*8 / 3*2*1.
I hope this helps.