If Greg rolls four fair six-sided dice, what is the probability that he rolls an equal number of 1's and 6's?
You mean "what is the probability of rolling 2 "ones" and 2 "sixes"?
The probability is: 4C2 * 2C2 =6 / 6^4 = 1 / 216
What about one 1 and one 6?
....and 3 ones and 3 sixes?
