00:01
So a coin is tossed 10 times, so that's 10.
00:04
Let's put down the number 10.
00:07
And we want to know the probability of getting heads five times, and the probability of getting ahead is 0 .5.
00:17
So 10 combination of 5, 5 being the number of times you do not get ahead.
00:26
So 10 minus 5 gives you 5.
00:30
P to the 5, q to the 5.
00:36
P to the success, q to the fail.
00:40
Success here in fail have equal numbers.
00:45
So, let's begin with 10c5.
00:49
That's similar to saying 10 factorial over 5 factorial times 5 factorial.
00:59
Multiplied by p which is 0 .5, power of 5 times 0 .5 to the power of 5.
01:10
Remember, that's part a.
01:13
So that will be equal to 0 .25 .25%.
01:24
Okay, so that's for part a.
01:27
Now, for part b.
01:32
Similarly, in part b, you're tossing the coin 10 times.
01:36
So again, 10c, but you want to get six heads...