Question

A bucket contains 50 lottery balls numbered 1-50. One is drawn at random. P( at least 20|prime number)

Answer 1

P( at least 20|prime number) = 0.4667

Explanation:

A probability is the number of desired outcomes divided by the number of total outocomes.

P( at least 20|prime number)

This is the probability of the number being at least 20, given that it is a prime number.

Desired outcomes:

Numbers that are at least 20 and prime.

They are: 23,29,31,37,4,43,47

There are 7 desired outcomes, so
`D = 7`

Total outcomes:

Prime numbers between 1 and 50.

They are: 2,3,5,7,11,13,17,19, 23,29,31,37,4,43,47

There are 15, so
`T = 15`

Probability:

`p = (D)/(T) = (7)/(15) = 0.4667`

P( at least 20|prime number) = 0.4667