Q4.Marks: +2.0UGC NET Paper 2: Computer Science 2nd January 2026 Shift 1
Which of the following statements are true if universe of discourse for all variables consist of all integers?
A. ∀n∃m(n2 < m)
B. ∃n∃m(n + m = 4 ∧ n - m = 2)
C. ∃n∃m(n2 + m2 = 5)
D. ∃m∀n(m + n = 0)
E. ∀m∃n(m + n = 0)
Choose the correct answer from the options given below:
1.A, B & C Only
2.A, B, C & D Only
3.A, B, C & E Only✓ Correct
4.B, C, E & D Only
Solution
The correct answer is A, B, C & E Only.
Key Points
Statement A: True because for every integer n, there exists an integer m such that n2 < m. For example, if n = 2, m can be 5.
Statement B: True because there exist integers n and m satisfying n + m = 4 and n - m = 2. Solving these equations gives n = 3 and m = 1.
Statement C: True because integers n and m exist such that n2 + m2 = 5. For example, n = 1 and m = 2.
Statement E: True because for every integer m, there exists an integer n such that m + n = 0. For instance, n = -m satisfies this condition.
Additional Information
Statement D: False because it states that there exists an integer m such that for all integers n, m + n = 0. This is not possible as m + n = 0 cannot hold true for all integers n.
The universe of discourse consists of all integers, which ensures that the conditions for statements A, B, C, and E are satisfied.