Question

Calculate the number of elements belonging to the sets described below:

The results of a survey of 40 incoming students show the following results:

16 students found a roommate through the school housing department.
12 students selected a roommate from a message board.
22 students knew their roommate personally.
7 students have both roommates from the housing department and message boards.
9 students have roommates from message boards and know personally.
11 students have roommates from the housing department and know personally.
5 students have roommates from all 3 sources

Answer 1

How many students did not report having roommates?

Answer 2

Is 8 the correct answer?

Answer 3

Anybody?

Answer 4

I am thinking 8 to witch would mean that the 22 students is just extra info

Answer 5

I'm just not 100% sure

Answer 6

ok I am not either but with the math I am doing that is what I am getting

Answer 7

yeah not sure

Answer 8

i am guessing that you have to fill in some sort of venn diagram
start in the middle

Answer 9

wanna try it?

Answer 10

Sure

Answer 11

we have to agree on a labelling
lets put A has housing dept, B as message board, C and know personally

Answer 12

5 students have roommates from all 3 sources

Answer 13

11 students have roommates from the housing department and know personally

Answer 14

Ok I understand that

Answer 15

i think this is right, lets continue

Answer 16

9 students have roommates from message boards and know personally.

Answer 17

7 students have both roommates from the housing department and message boards.

Answer 18

you see where i am getting the numbers from right?

Answer 19

oh ok i see how this is going

Answer 20

yeah i do

Answer 21

22 students knew their roommate personally.

Answer 22

12 students selected a roommate from a message board.