Question

3. If A = (1, 2, 3, 4} and B = {2, 4, 9) then Find a) (A-B) n (B - A) b) n(A-B ) + n(B -A)​

Answer 1

Answer:

a) A-B = ( 1,2,3,4} - {2,4,9}= {1,3} ( elements of a that are not in b )

B-A= {9} ( elements of b that are not in a)

(A-B) intersection (B-A)

= {1,3,} intersection {9}

= null set ( no element is common)

b) n( A-B) = {1,3}

n ( B-A)= {9}

n(A-B ) + n(B -A)= { 1,3,9}