Let A = {x:x N}, B = {x:x = 2n, n N), C = {x:x = 2n – 1, n N} and, D = {x:x is a prime natural number} Find:

i. A B


ii. A C


iii. A D


iv. B C


v. B D


vi. C D

A = All natural numbers i.e. {1, 2, 3…..}


B = All even natural numbers i.e. {2, 4, 6, 8…}


C = All odd natural numbers i.e. {1, 3, 5, 7……}


D = All prime natural numbers i.e. {1, 2, 3, 5, 7, 11, …}


i. A B


A contains all elements of B.


B A


A B = B


ii. A C


A contains all elements of C.


C A


A C = C


iii. A D


A contains all elements of D.


D A


A D = D


iv. B C


B C = ϕ


There is no natural number which is both even and odd at same time.


v. B D


B D = 2


2 is the only natural number which is even and a prime number.


vi. C D


C D = {1, 3, 5, 7…}


Every prime number is odd except 2.


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