A survey was conducted to know the hobby of 220 students of class 9. out of which 130 students informed about their hobby as rock climbing and 180 students informed about their hobby as sky watching. there are 110 students follow both the hobbies. then how many students do not have any of two hobbies? how many of them follow the hobby of rock climbing only? How many students follow the hobby of sky watching only?
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=The total no.of students = n(U)= 220
=The no.of students having hobby as rock climbing =n(A)= 130
=The no.of students having hobby as sky watching =n(B) =180
=The no.of students having both hobbies=n(A intersection B)= 110
=n(A union B)=n(A)+n(B)-n(A intersection B)
=n(A union B)= 130+180-110=200
= The no.of students without any hobby
n(U ) -n(A union B)=220-200=20
=The no.of students having hobby as rock climbing =n(A)- n(A intersection B) =130-110=20
=
The no.of students having hobby as sky watching =n(B) -n(A intersection B)=180-110=70
=The no.of students having hobby as rock climbing =n(A)= 130
=The no.of students having hobby as sky watching =n(B) =180
=The no.of students having both hobbies=n(A intersection B)= 110
=n(A union B)=n(A)+n(B)-n(A intersection B)
=n(A union B)= 130+180-110=200
= The no.of students without any hobby
n(U ) -n(A union B)=220-200=20
=The no.of students having hobby as rock climbing =n(A)- n(A intersection B) =130-110=20
=
The no.of students having hobby as sky watching =n(B) -n(A intersection B)=180-110=70
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