This is a binomial probability experiment. Each trial is independent of one another, ie each roll is independent. The probability of getting an even number is 3/6 = 1/2 = 0.5 and that probability does not change from roll to roll. Furthermore, the value of n is fixed and not infinitely large. Lastly, each trial outcome comes down to two choices: either you get an even number, or you don't. So we've met the requirements of a binomial probability distribution.
The values of n, p and q are:
- n = 30 = sample size
- p = 0.5 = probability of getting an even number
- q = 0.5 = probability of not getting an even number.