If there is an 80% chance of rain and a 30% chance of wind and rain, what is the probability that it is windy, given that it is rainy? Round your answer to the nearest percent.
We suppose the total chance is 100%. So the chance of wind and rain accounts for 30%. Then it is given rainy. So the total chance will change to 80% and the chance of wind and rain remains constant. Then you can get the answer should be 30%/80%=37.5%≈38%.