Answer:
93
Step-by-step explanation:
Let
U=Universal set=257
A= Brussels sprouts
B= Broccoli
C= Cauliflower
[tex]n(A)=69[/tex]
[tex]n(B)=91[/tex]
[tex]n(C)=55[/tex]
[tex]n(A\cap B)=25[/tex]
[tex]n(B\cap C)=20[/tex]
[tex]n(A\cap C)=21[/tex]
[tex]n(A\cap B\cap C)=15[/tex]
We have to find the number of students who do not like any of these three vegetables.
We know that
[tex]n(A\cup B\cup C)=n(A)+n(B)+n(C)-n(A\cap B)-n(B\cap C)-n(A\cap C)+n(A\cap B\cap C)[/tex]
Substitute the values then we get
[tex]n(A\cup B\cup C)=69+91+55-25-20-21+15=164[/tex]
[tex]n(A\cup B\cup C)'=U-n(A\cup B\cup C)=257-164=93[/tex]