Basic stats question using multiplication rules

Statistics
Tutor: None Selected Time limit: 1 Day

I'm just learning stats. A little confusing. Here s the question:

Out of 100 people, 14 are Rh- (blood type), 40 are type A, and 5 are universal donors (Rh- and type A). If 4 of the 100 subjects are randomly deleted, find the probability that they are all universal donors. A) assume selections are made with replacement B) assume selections are made w/o replacement.  

How to do this with P(A & B)=P(A) x P(B) ?

I know how to find the probability of selecting one universal donor, but not four times. 

Apr 26th, 2015

This would be done the same way; the probability of 4 of the universal donors being deleted is 5/100x4/99x3/98x2/97. Each scenario would be viewed independently.

Apr 26th, 2015

Oops, meant to write "randomly selected", but I don't think that changes anything.

Apr 26th, 2015

It should be the same.

Apr 26th, 2015

And my first response is for without replacement; if it was with replacement, then it would just be 5/100^4

Apr 26th, 2015

Wow, thanks. I just found this site. Pretty amazing. Thanks so much for your help!

Apr 26th, 2015

Not a problem!

Apr 26th, 2015

Studypool's Notebank makes it easy to buy and sell old notes, study guides, reviews, etc.
Click to visit
The Notebank
...
Apr 26th, 2015
...
Apr 26th, 2015
Dec 6th, 2016
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer