Question

Can someone please help me with this question?

http://prntscr.com/ji5rpp

Answer 1

`28xx(1/2)^6xx(1/2)^2~~10.94%`

Explanation:

The question is that a coin is tossed 8 times and we're looking for the probability of exactly 6 tails.

Let's work the question this way - first off we know that the probability of getting tails is `1/2` on any given flip. We want exactly 6 of them, so that's `(1/2)^6`.

We also have to account for not getting tails - the probability of not getting tails on any given flip is also `1/2` and we want exactly 2 of them, so that's `(1/2)^2`.

Lastly, there are a number of different ways we can get 6 T and 2 H:

TTTTTTHH
HHTTTTTT

and so on. In fact, there are `((8),(6))` ways of getting 6 Tails and 2 Heads. That's `((8),(6))=28`.

In all then, we have:

`28xx(1/2)^6xx(1/2)^2~~10.94%`