.
Age S B A Totals
Y 8 2 18 28
M 16 8 12 36
O 34 17 12 63
Totals 58 27 42 127
Using contingency table:
Find O' union (S union A)
~~~~~~~~~~~~~~~~
In your post, the table is prepared very accurately - so accurately,
that it is a pleasure to work with it and to help you.
Now listen to me attentively.
They want you determine the number of elements in the set { O' union (S union A) }.
Here O' means the complement to the line O. This complement is the union of lines Y and M.
So, to the lines Y and M, you should add the parts of columns S and A, that are outside lines Y and M.
Lines Y and M give you the totals 28 + 36 = 64.
To it, you should add the parts of columns S and A, that are outside the lines Y and M;
in other words, you should add (34+12) to 64. It will give you the ANSWER 64 + (34+12) = 110.
Solved.
