PLZ HELP OR I GET I N TROUBLE !! :(
Answers
The value in box of circle B is 3 and the value in box which belongs in both circle B and S is 6 and value which belongs in circle S is 1 and the value of box outside both the circle is 2.
Step-by-step explanation:
In given Venn diagram
ε = class of 12 pupils
pupils who have brother B = 9
pupils who have sister S = 7
pupils who have neither brother nor sister = 2
Hence the Venn diagram is drawn in the attachment for your reference.
n(E) =12
n(neither B nor S) = 2
So, n(B or S)= n(E) - n(neither B nor S)= 12-2=10
n(B) = 9
n(S) = 7
Now, addition theorem,
n(B or S) = n(B) + n(S) - n(B and S)
\begin{gathered}10=9+7-n(B\ and \ S)\\n(B\ and \ S) = 6\end{gathered}
10=9+7−n(B and S)
n(B and S)=6
So the value in box which is in both circle B and S is 6.
So the Box which contains only brothers = n(B) - n(B and S) = 9 - 6 = 3
Value in box of circle B is 3.
So the Box which contains only Sisters = n(S) - n(B and S) = 7 - 6 = 1
Value in box of circle S is 1.