Question

If there is 10% chance of sun tomorrow and a 20% chance of wind and no sun, what is the probability that it is windy, given that it is not sunny?

Answer 1

Answer: 22%

Explanation:

I’m always right :)

Answer 2

0.2222

Explanation:

Let A be the event that there is sun

Let A' be the event that there is no sun

Let B be the event that there wind

Then we have

P(A) = 0.1

P(A') = 0.9

P(A' and B) = 0.2

We need P(B|A')

The formula for P(B|A') is...

P(B|A') = P(A' and B)/P(A')

Plug in what we are given and simplify...

P(B|A') = 0.2/0.9

P(B|A') = 0.2222