Question

There are 6 students who all want to be in a group of 3 people chosen to speak at graduation. How many different groups can be chosen?

Answer 1

18?

Answer 2

6!/3!3!2!

Answer 3

6 students for the first spot
5 for the second
4 for the third
6*5*4=120
then divide by 3*2*1=6
20

Answer 4

n!/r!(n-r)!

Answer 5

n is the number you chose from, r is the number you are choosing.