00:01
So since the coin is fair, and then the probability of getting head or tail is equal to each other, which is both .5.
00:10
So for the first question, we have an equal number of heads and tails, which means that we have five heads and five tails.
00:16
So we need to choose which five or has.
00:19
We choose five from ten to determine the positions of heads, and then times the probability.
00:26
And also for the remaining five, we need to have the probability for tail.
00:30
So this is the probability we have for the first question, which is 0 .2461.
00:36
The first three are all heads, which is probability 5 to the power of 3, which is 0 .1 to 5.
00:44
And question 3, both happened an equal number of heads and tails, and the first 3 are heads.
00:55
So first 3 are heads with probability of this.
00:58
And then for the remaining seven tosses, we have to choose two heads, then to make sure that the number of heads and the number of tails are equal to each other.
01:14
And then for the remaining five, we make it tails, which has a probability of 0 .5 to the power of 5...