1.which of the following represents an empty or null set?
a.A={a/a is a vowel letter}
b.B={b/b is whole number between 8 and 9}
c.C={c/c is primary color}
d.D={d/d is two-legged animal}
2.which of the following is not a well-defined set?
a. collection of students in grade-7
b.collection of all Mathematics teachers in BNHS
c.collection of good student in class
d.collection of male students in a public school
3.what is the cardinality of set B consisting of the letters in the English Alphabet?
a.n(B)=24 b.n(B)=4
c.n(B)=3 d.n(B)=5
4.what is the cardinality of set Q consisting of number {1, 3, 5 ,7}?
a.n(Q)=2 b.n(Q)=4
c.n(Q)=3 d.n(Q)=5
5.what is A U B?
a.A u B={1, 7, 9} b.A u B={1,2,4,5,7,8}
c.A u B={ } c.A u B={2,4,5,8,9}​