UGC NET · PAPER 2
UGC NET Paper 2 Computer Science – Unit 1: Discrete Structures and Optimization PYQ (December 2024)
Q7. Which one of the following is NOT a basic solution of the system of linear equations
x₁ + 2x₂ + x₃ = 4
2x₁ + x₂ + 5x₃ = 5
x₁ + 2x₂ + x₃ = 4
2x₁ + x₂ + 5x₃ = 5
- x₁ = −1, x₂ = 2, x₃ = 1
- x₁ = 2, x₂ = 1 (x₃ = 0)
- x₁ = 5, x₃ = −1 (x₂ = 0)
- x₂ = 5/3, x₃ = 2/3 (x₁ = 0)
Q14. Match List I with List II: match the logically equivalent propositions
| List I | List II |
|---|---|
| A. p → q | I. (p ∧ q) ∨ (¬p ∧ ¬q) |
| B. ¬(p ∨ (¬p ∧ q)) | II. ¬p ∨ q |
| C. p ↔ q | III. ¬(p ∨ q) |
| D. ¬(p ↔ q) | IV. ¬p ↔ q |
- A-I, B-III, C-II, D-IV
- A-I, B-II, C-III, D-IV
- A-II, B-III, C-I, D-IV
- A-II, B-III, C-IV, D-I
Q22. The probability that A hits a target is 1/4, and the probability that B hits the target is 2/5. Both shoot at the target. What is the probability that at least one of them hits the target, i.e., that A or B (or both) hit the target?
- 3/5
- 11/9
- 2/20
- 11/20
Q40. If x and y are elements in a group G and if x⁵ = y³ = e, where e is the identity of G, then the inverse of x²yx⁴y² must be
- y²xy²x⁴
- yxy²x³
- yx⁶y⁶x³
- x⁴y²x²y
Q58. Arrange the following graphs on the basis of number of edges in increasing order (for large n):
A. Kₙ (Complete Graph)
B. Cₙ (Cycle graph)
C. Wₙ (Wheel graph)
D. Kₙ,ₙ (Complete Bipartite Graph)
E. Qₙ (n-cube graph)
Choose the correct answer from the options given below:
A. Kₙ (Complete Graph)
B. Cₙ (Cycle graph)
C. Wₙ (Wheel graph)
D. Kₙ,ₙ (Complete Bipartite Graph)
E. Qₙ (n-cube graph)
Choose the correct answer from the options given below:
- A, B, C, D, E
- B, C, A, D, E
- A, B, C, E, D
- E, D, C, A, B
Q62. A linear programming problem (LPP) is as follows: Min z = 30x − 18y, subject to the constraints 3x + 4y ≤ 60, 5x − 3y ≥ 20 and x, y ≥ 0. In this feasible region, the solution(s) of the LPP is/are
A. (4, 0)
B. (2, 0)
C. (7, 5)
D. (0, 15)
E. (8, 5)
Choose the correct answer from the options given below:
A. (4, 0)
B. (2, 0)
C. (7, 5)
D. (0, 15)
E. (8, 5)
Choose the correct answer from the options given below:
- A and C only
- B only
- E only
- D only
Q69. Which of the following graphs is/are planar?
Graph A (vertices a–f): edges ab, ac, bd, cf, de, ef, bf, cd.
Graph B (vertices a–f): edges af, ae, ad, ac, bf, bc, bd, ef, df, ce.
Graph C (vertices a–i): edges hi, hg, he, ia, if, ag, ae, ad, ab, bf, be, cf, cd, de, fg.
Choose the most appropriate answer from the options given below:
Graph A (vertices a–f): edges ab, ac, bd, cf, de, ef, bf, cd.
Graph B (vertices a–f): edges af, ae, ad, ac, bf, bc, bd, ef, df, ce.
Graph C (vertices a–i): edges hi, hg, he, ia, if, ag, ae, ad, ab, bf, be, cf, cd, de, fg.
Choose the most appropriate answer from the options given below:
- A and C only
- B only
- A only
- A and B only
Q89. Which of the following statements are true about sets?
A. 0 ∈ ∅
B. ∅ ∈ {0}
C. ∅ ∈ {∅}
D. {∅} ∈ {∅}
E. {∅} ⊂ {∅, {∅}}
Choose the correct answer from the options given below:
A. 0 ∈ ∅
B. ∅ ∈ {0}
C. ∅ ∈ {∅}
D. {∅} ∈ {∅}
E. {∅} ⊂ {∅, {∅}}
Choose the correct answer from the options given below:
- A, B, C, D and E
- A, B, C and E only
- A, C only
- C and E only