00:01
So we are given a tetrahedral dye, and we are told that we are going to roll it until we end up with all four faces coming up at least once.
00:13
And we are asked to find the probability of this happening within the first four rolls.
00:19
So this is going to happen this way.
00:26
A tetrahedral die has four sides.
00:30
So all of our initial fractions, because we are rolling four times, we'll have a four on the bottom because we have four outcomes.
00:44
Now, what we need to do here is we need to ask ourselves for each role, what is the probability that we are not going to succeed? or that we are going to succeed.
01:02
So for the first one, what's the chance that we're going to get a number that we haven't already gotten? well, okay.
01:11
We haven't rolled any numbers yet, so we are guaranteed to succeed with all four options...