A building has 6 entrances. 4 people were about to enter the building. Many ways that can be taken so that they can enter the building using different doors are...A.10, B.24, C.256, D.324, E.360

Question

I have never seen these types of Questions. I will appreciate if someone could help me :)

Answer 1

6 doors and 4 students.

We are trying to find the number of permutations of 6 doors between 4 students.

# permutations = n! / (n-r)! --- for this case n = 6 and r = 4

So, 6!/(6–4)! = 6!/2! = (6*5*4*3*2*1)/(2*1) = 6*5*4*3 = 360 ways..