Math Probability

Question

If the probability that it will rain tomorrow is 1/5, what is the theoretical probability that it will not rain tomorrow?

A- 4/5

B- 3/5

C- 2/5

D- 2/10

Answer 1

Hey Kalise I hope this can answer your question. So the problem is saying that their is a 1/5 percent of raining that is the same thing as 20 percent. So since decimals/ fractions are based on 100, 100-20=80 and that is the same thing as 4/5 so their is an 80 percent chance that it will not rain, hopefully that helps, and feel free to contact me if you want to start tutoring.

Answer 2

"rain" and "not rain" are complementary events, meaning that the sum between them must be 1. so the formula you can use on this one is

P(not rain) = 1 - P(rain) = 1 - 1/5 = 4/5

meaning that the theoretical probability that it will not rain tomorrow is 4/5