00:01
So we're given a bag of marbles that has seven white marbles, five red marbles, and three green marbles.
00:05
So the total number of marbles in the bag is 15.
00:10
And we're asked to determine the probability that when we draw two marbles, the first one is red and the second one is white.
00:18
So we want to know what happens, what's the chance is that the first one i draw is red and the second one that i draw is white.
00:25
And so we're asked to do this twice, first with replacement and second without replacement.
00:31
So the chances of pulling a red marble originally are five out of 15 or one third.
00:38
And the chances of pulling a marble if i replace, let's assume that i pull out a red marble the first time.
00:44
If i replace it into the bag, i still have 15 marbles in the bag.
00:47
So the chances of pulling a white marble after that with replacing the red marble that i originally drew is 7 out of 15...