COMEDK20269 May 2026Morning ShiftMathematicsSets and RelationsActual
If A = x : x is the first three odd numbers B = 2x + 3 : 0 x true
Options
- AA B =
- BA B is a singleton set
- CA B
- Dn(B) = 5
Correct answer
B. A B is a singleton set
Step-by-step solution
The first three odd natural numbers are 1, 3 , and 5 . A = 1, 3, 5 For set B , the condition is 0 x Substituting these values into 2x + 3 : For x = 1 , 2(1) + 3 = 5 For x = 2 , 2(2) + 3 = 7 For x = 3 , 2(3) + 3 = 9 For x = 4 , 2(4) + 3 = 11 B = 5, 7, 9, 11 Finding the intersection of sets A and B : A B = 1, 3, 5 5, 7, 9, 11 = 5 Since A B contains exactly one element, it is a singleton set. Also, n(B) = 4 . Answer: A B is a singleton set