Question

What is the cardinality of the set A = (x:4<2x-2<12, x is an integer)

Answer 1

Answer:

A ={xϵz:2

(x+2)(x

2

−5x+6)

=1}

2

(x+2)(x

2

−5x+6)

=2

0

⇒x=−2,2,3

A={−2,2,3}

B={xϵZ:−3<2x−1<9}

B={0,1,2,3,4}

A × B has is 15 elements so number of subsets of A × B is 2

15

.