Answer:
The probability that it is windy, given that it is rainy is:
62.5%≈63%
Explanation:
Let A denote the event that it will rain.
B denote the event that it is windy.
A∩B denote the event that it is rainy and windy.
Let P denote the probability of an event.
i.e. we have:
P(A)=0.80
( Since there are 80% chance of rain)
P(A∩B)=0.50
(Since there are 50% chance of wind and rain)
We are asked to find:
P(B|A)
We know that:

Hence, the probability in percent is:
62.5%≈63%