Answer :
Answer: There are 13 people who like country music.
Step-by-step explanation:
Since we have given that
Number of people who like rock n(A) = 14
Number of people who like classical n(B) = 17
Let the number of people who like country n(C) be 'x'.
Number of people who like both rock and country = 11
Number of people who like both rock and classical = 9
Number of people who like both country and classical = 12
Number of people who like rock, country and classical = 8
As we know the formula:
n(A∪B∪C)=n(A)+n(B)+n(C)-n(A∩B)-n(B∩C)-n(C∩A)+n(A∩B∩C)
[tex]20=14+17+x-11-9-12+8\\\\20=31+x-32+8\\\\20=x+7\\\\20-7=x\\\\x=13[/tex]
Hence, there are 13 people who like country music.