# Math Help - Statistics - probability

1. ## Statistics - probability

What is the probability that any student has a birthday on a Saturday?
What is the probability that any student's birthday is not on a Saturday?
What is the probability that any two students don't have a birthdayn a Saturday?
What is the probability that any three students don't have a birthday on a Saturday?
What is the probabilty that any 20 students don't have a birthday on a Saturday?

2. ## Re: Statistics - probability

- Probability = Number of successes / Total number of possibilities
- Independent probabilities can be multiplied.

1) How many days in a week, and how many of those are Saturday?
2) How many days in a week, and how many of those are not Saturday?
3) Take the answer for two, and now you have two independent probabilities.
4) Same as 3) except you have 3.
5) Same as 4) except you have 20.

3. ## Re: Statistics - probability

Originally Posted by elmidge
What is the probability that any student has a birthday on a Saturday?
What is the probability that any student's birthday is not on a Saturday?
What is the probability that any two students don't have a birthdayn a Saturday?
What is the probability that any three students don't have a birthday on a Saturday?
What is the probabilty that any 20 students don't have a birthday on a Saturday?
Why are you asking these questions? They appear to be course work for an introductory course in probability but you seem to be saying that you know nothing about probability.