Question

A bin contains beach balls. Some beach balls have yellow on them. Some beach balls have blue on them. Some beach balls have yellow and blue on them. Let Y be the set of balls with yellow on them and B be the set of balls with blue on them.

What does P(Y∪B)=6 mean?

Answer 1

There might be typo error. The probability of any quantity is always less than or equal to 1. So, the probability
`P(Y\cup B)=6` is not possible. It should be
`P(Y\cup B)=0.6`.

Answer:

It means that the probability of getting a yellow or blue ball is 0.6.

Explanation:

Given:

Y = set of yellow balls

B = set of blue balls

Therefore, the union of both the balls is given by the set Y U B.

The set Y U B represents the set that contains either yellow balls or blue balls but do not contain those balls that have both yellow and blue on them.

So,
`n(Y\cup B)=n(Y)+n(B)-n(Y\cap B)`

Now, if
`P(Y\cup B)=0.6`, it means that the probability of getting a ball that has either yellow or blue on it is 0.6. In other words, if there are 100 balls, then the chances of getting a ball having either yellow or blue on it is 60%.