From 5 employees at a company, a group of 3 employees will
be chosen to work on a project. How many different groups
of 3 employees can be chosen?

Question

From 5 employees at a company, a group of 3 employees will 
be chosen to work on a project. How many different groups 
of 3 employees can be chosen?

ksaimouli · Answer

@zepdrix

ksaimouli · Answer

is their any easy technique it is hard to do mentally

ksaimouli · Answer

what i do is (3)(3) because 3 people only once

zepdrix · Answer

So this is probability stuff right?
Since `order` doesn't matter this is a Combination problem, not a Permutation.

Understand what I mean by "order doesn't matter"?

If Bob, Suzy and then Tom get picked.
That's the same as Suzy, Tom and then Bob getting picked.

The order they were picked in doesn't matter.

The notation can be written like this, $\large _5C_3$
Which would be read, "5 choose 3".

$$\large _nC_r \qquad = \qquad \frac{n!}{r!(n-r)!}$$

zepdrix · Answer

(3)(3)? Hmm maybe there is a simple way to do this like by building a tree, and such. But I'm not really comfortable with this subject of material to explain it that way :\ heh

ksaimouli · Answer

10

zepdrix · Answer

Yah that sounds right c: