venn diagram: Blood samples of 100 people were tested....

wine15

New member
Joined
Feb 20, 2007
Messages
3
blood samples of 100 people were tested. the A,B, and Rh antigens were found in the blood of 32,33, and 74 people, respectively. None of the antigens was found in 13 samples. Ten samples contained the A and Rh antigens only, 9 contained the B and Rh antigens only, 6 contained the B antigen only and 3 contained the A and B antigens only.

a. Draw a venn diagram displaying the given data and the number of elements on each basic region.
b. how many samples contained the A and B antigens?
c. How many samples do not contain the Rh antigen?
 
Well, do it. It takes three circles, mutually intersection, and a box around them all. Let's see what you get.
 
hmm

yeah i got that far. I got 42 samples for Rh, but I don't think thats correct.
 
Re: hmm

wine15 said:
yeah i got that far. I got 42 samples for Rh, but I don't think thats correct.
How did you get this number? (Describe your work and reasoning, just like you'd want the tutors to do for you.)

On what basis do you think your answer is wrong? (Please be specific. For instance, your reason might be that "this is multiple-choice, and I just guessed, but there are three other answers, so odds are that I guessed wrong; please give me the solution.")

Thank you.

Eliz.
 
lost

well its not multiple choice. in the problem it says ten contained A and Rh so i put that in the intersecting circle of a and rh. then it says b and rh have 9 so i put nine in the intersection of b and rh. I put 13 in the middle of the 3 circles , but this is where i am getting lost.
 
13 does not go in the middle section. It goes outside ALL the circles, but inside the box. "None of the antigens was found in 13 samples". You put it in the "All Antigens were found" section.

Your key is the B-antigen

1) There are 33 total
2) 6 have only the B - This leaves 27
3) 3 have A&B - This leaves 24
4) 9 have Rh&B - This leaves 15 for the very center of the three circles.

Now what?
 
Top