Recent content by eldani

I had exactly the same problem! When it was really bad, I tried various pillows, but it wasn't until I switched mattresses that the pain and headaches finally began to subside. I liked the new mattress so much (Perfect Dreamer from Nine Clouds) that I bought exactly the same one when I moved...

(I felt shell-shocked after that quiz)

I found it in 3 different places online - one was on this site: https://www.physicsforums.com/showthread.php?t=336770

My faulty memory - I had mixed up disjoint and independent. For independent, it seems like the easiest calculation is: P(A∪B∪C∪D) = 1 - [1-P(A)][1-P(B)][1-P(C)][1-P(D)] But don't quote me on that! Like I said - I'm a newb.

Well, I think that means that these are still true: P(A∩B∩C) = P(A)P(B)P(C) and P(A|B) = P(A)

Hi LCKurtz, I'm a newbie, so I may very well have it wrong, but the full question states: A school has a computer lab that is closed for the summer, when no students are there, and then is re-opened in the fall. Sometimes, a computer in the lab that worked before the lab closed is found to not...

Since they're independent, P(A∪B∪C∪D) = P(A) + P(B) + P(C) + P(D) Also, P(A∩B∩C) = P(A)P(B)P(C) and P(A|B) = P(A) I find that the text he quotes from (there's a link to the PDF version of it on the course site) is very useful. Not that I'm having an easy time of it!

Hey zeion - you must be taking the same stats course as me. Make sure to notice that the question specifies that the events are independent!

you're right vela - 6 choose 3 gives 20.

Just one thing - for question 3 you've got 2^3 = 20. Should be 8.