Question

A Weather Forecaster, predicts that their is a 50% chance of rain on Saturday and a 40% chance of rain on Sunday. If these probabilities are correct, what is the probability that it will rain both days?

Answer 1

20% chance.

Explanation:

If you do not know the formula, here is a quick intuitive method.

Construct the sample space in a square with 4 divisions

split one side into 1/2 and 1/2 and the other side into

.4 and .6

You can easily see that the day that it will rain on both days is .2 (1/2*.4)

or 20%