If you are a member of this class, what is the probability that at least one of the other 11 students rolls the same number as you do?

I assume we are talking about rolling a fair die with 6 numbers.

The probability that none of the 11 students throw the same number as you do is (5/6)^11  =  0.135 

So probability at least one throws same mumber = 1 - 0.135  =  0.865 Answer

He will need 2,898 pieces of paper