Question

If there's a three day rain forecast for the probability of rain , 70% Friday, 70% Saturday, 70% Sunday A) work out the probability that it will rain on all three days B) work out the probability that it will rain on exactly two consecutive days

Answer 1

a) 34.3%

b) 49%

Explanation:

In order to find the probability of a sequence of events, we need to multiply each individual probability by the others in decimal form. Therefore, we need to turn these probabilities into decimal form by dividing them by 100 like so..

70% / 100 = 0.70

Now we multiply all of them together and multiply the product by 100 to get the percentage.

0.70 * 0.70 * 0.70 = 0.343

0.343 * 100 = 34.3%

34.3% is the probability of it raining on all three days. Now to find the probability of it raining on two consecutive days we do the same but multiply only 2 probabilities

0.70 * 0.70 = 0.49

0.49 * 100 = 49%