NTA Abhyas JEE Main2020MathematicsSets and RelationsPractice
Let Z be the set of integers, if A = x ∈ Z : x - 3 x 2 - 5 x + 6 = 1 and B = x ∈ Z : 10 < 3 x + 1 < 22 , then the number of subsets of the set A × B is
Options
- A2 6
- B2 8
- C2 15
- D2 9
Correct answer
A. 2 6
Step-by-step solution
For A , x - 3 = 1 ⇒ x = 2,4 or x 2 - 5 x + 6 = 0 ⇒ x = 2,3 but x ≠ 3 ∴ A = 2,4   For B , B = 4 ,5 , 6 n A × B = 6 ∴ number of subsets = 2 6