ELI5: Explain Like I'm 5

bayes theorem

Bayes' Theorem is a way to figure out how likely something is. It's like a math equation that helps us figure out how something is related to two other things. For example, we can use Bayes's Theorem to figure out the chance of it raining today if it rained yesterday. To do that, we need to know two different pieces of information:

1. The chance of it raining today, no matter what the weather was like yesterday.
2. The chance of it raining today if it rained yesterday.

Now, the math equation helps us figure out the answer. It takes the two pieces of information and multiplies them together. Then it adds them together to get the answer. So, if it is 50% likely to rain today and 70% likely to rain today if it rained yesterday, then the chance of it raining today if it rained yesterday is 50% x 70% = 35%, so the chance of it raining today if it rained yesterday is 35%.