Mathematical quiz grade 9 set

1.U∩ϕ=?,U is a universal set.

• ϕ

• U

• U-ϕ

• ϕ-U

2.In a survey of 350 students in a school 200 liked chitwan 220 like pokhara and 120 liked both places ,how many students like neither of places.

• 45

• 40

• 50

• 55

3.if n(A)=20 ,n(A∩B)=13 n only(A)=?

• 10

• 7

• 9

• 8

If U=50,n(AUB)=19,n(AUB)', ' refers to complement

• 21

• 41

• 32

• 31

What is set?

• Collection of objects

• Collection of well defined objects

• Well defined collection of objects

• None of them

If A and B are disjoint sets then n(AUB)=?

• n(A)+n(B)

• n(A)+n(B)-n(A∩B)

• n only(A)+n only (B)

• None of them