gordon tosses a fair die four times. What is the probability that he will toss exactly two 5s

gordon tosses a fair die four times. what is the probability that he will toss exactly two 5s

If the probability of something occurring is p, then the probability of it not occurring is (1-p), and the probability of it occurring k times out of n tries is:

Prob (k occurrences in n tries) = C(n,k)p^k(1-p)^{(n-k)}

For this problem do you know what the values for p, n and k are? Post back with what you get for an answer and we'll check it for you.