Answer:
b. 27,405
Step-by-step explanation:
So, we have a total population of 30 (n) and we sample 4 (r) from it.
Now, is it a combination or a permutation? Does the order matter? Is it important that the teacher picked John before Andrew? No. So, it's a combination:
C(n,r)=C(30,4)
[tex]C(30,4) = \frac{30!}{4| (30-4)!} = 27405[/tex]
So, the teacher has 27,405 ways to combine groups of 4 students from his 30-student class.
