A school director must randomly select 6 teachers to participate in a training session. There are 26 teachers at the school. In how many different ways can these teachers be selected, if the order of selection does not matter?

A. 165,765,600
B. 178,330
C. 102,118,800
D. 230,230

Question

A school director must randomly select 6 teachers to participate in a training session. There are 26 teachers at the school. In how many different ways can these teachers be selected, if the order of selection does not matter?

 		A.	165,765,600
 		B.	178,330
 		C.	102,118,800
 		D.	230,230

jadeishere · Answer

So this would be a combination, right? Since order doesn't matter in the selection of the teachers.
the formula of combination is n! / (n-r)!r!

anonymous · Answer

$$26\times25\times24\times23\times22\times21\div720$$

jadeishere · Answer

n = 26 (Total amount of teachers
r = 6 (select amount)

so 26! / (20!6!)

230230