How many relay teams of 4 members can be cosen from a 9 member team to run in a relay race?

Question

probability word problem0

Answer 1

Since order does not matter, we use combinations.

 

n! / (n - r)! r!

 

Thus,

 

9!

__

 

(9 - 4)! 4!

 

Simplify,

 

9!

___

 

5! 4!

 

Expanded and reduced,

 

9*8*7*6

_______

 

4*3*2*1

 

 

Answer: 126