Hi there...Can please somene help with this question?

a four sided (tetrahedral) die has a different number - 1, 2, 3, or 4 affixed to each side. on any given roll, each of the four numbers is equally likely to occur. if the die is rolled 20 times, the number of occurrences of each side is recorded. what is the probability of obtaining four 1's, five 3's and 11 even numbers?