Question

if A ={2x:x€N} B={3x:x€N} C={5x: x€N} then find A intersect B , B intersect C, (A intersect B) intersect C

Answer 1

Answer:

A∩B={6,12,18,24............}

B∩C={15,30,45............}

A∩B∩C={30,60,90............}

Step-by-step explanation:

Concept used:

The intersection of two sets A and B is the set of elements common to both A and B

Given:

A={2,4,6,8,.............}

B={3,6,9,12............}

C={5,10,15............}

A∩B=set of all common multiples of 2 and 3

A∩B=set of all multiples of 6

A∩B={6,12,18,24............}

B∩C=set of all common multiples of 3 and 5

B∩C=set of all multiples of 15

B∩C={15,30,45............}

A∩B∩C=set of all common multiples of 2 ,3 and 5

A∩B∩C=set of all multiples of 30

A∩B∩C={30,60,90............}

Answer 2

Answer:

B=x|x€and 3x-1=0} finite or infinite