Given:
Combination of objects 4 objects taken two at time
To find:
How many combinations can be made with selecting two at a time.
Explanation:
Combination of n things taking r at a time,
[tex]^nC_r=\frac{n!}{\left(n-r\right)!r!}[/tex]Solution:
Combination of 4 objects taking 2 at a time,
[tex]\begin{gathered} ^4C_2=\frac{4!}{\left(4-2\right)!2!} \\ =\frac{4!}{2!2!} \\ =6 \end{gathered}[/tex]This is the required answer.
