Pick a number from the following list: 1 2 3 4 write it down. if each student in the class of 50 were also to pick a number, how many would you guess has selected the same number as you

There are 4 choices to pick from (1,2,3,4) so the odds of someone randomly picking one number would be 1 in 4

P(1)=1/4
P(2)=1/4
P(3)=1/4
P(4)=1/4

If 50 students were to also pick a number at random, then...

50*1/4=12.5

12.5 students would likely choose the same number as you did.

Since you can't have .5 of a student, lets round 12.5 to 13

Answer=13 students

13 students I had that question before