00:01
For this exercise, we are rolling a die six times, and we are asked for the probability of getting at least one even number.
00:10
So for on any individual roll, the number of ways of getting an even number are to roll a two, a four, or a six.
00:20
So that is three out of six possible outcomes.
00:24
And so that means for any given roll, the probability of rolling an even number is equal to one -half.
00:33
So let's define a random variable as the number of even rolls out of six rolls of the die.
00:47
Now each roll of the die can be viewed as a bernoulli trial, that is there are only two possible outcomes of interest.
00:54
Either it's even or it's not.
00:57
And each roll of the die can also be viewed as independent from the other roles.
01:02
The number of successes in a set of independent bernoulli trials, is a binomial random variable...