Respuesta :

Answer:

45

Step-by-step explanation:

This is a combination question: how many ways can you pick 2 people from a group of 10?

Using the notation C(10, 2) for the number of combinations of 10 things chosen 2 at a time...

[tex]C(10, 2)=\frac{10!}{2!(10-2)!}=\frac{10!}{2!\cdot 8!}=\frac{10\cdot 9}{2\cdot 1}=45[/tex]