Question

To conduct an experiment, researches randomly select five students from a class of 18. How many different groups of five students are possible? groups

Answer 1

8568 ways

Explanation:

We have to in this particular case the order to find a 5 person group out of a class of 18, when order does not matter, we use combinations. In this case n = 18 and r = 5.

We have that the combination formula is:

nCr = n! / (r! * (n-r)!)

replacing we have:

18C5 = 18! / (5! * (18-5)!)

18C5 = 8568

What it means in total are 8568 ways of arms groups.