#### 12th Standard Maths Discrete Mathematics Equations English Medium Free Online Test One Mark Questions with Answer Key 2020 - 2021

12th Standard

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Maths

Time : 00:10:00 Hrs
Total Marks : 10

Answer all the questions

10 x 1 = 10
1. Subtraction is not a binary operation in

(a)

R

(b)

Z

(c)

N

(d)

Q

2. If a compound statement involves 3 simple statements, then the number of rows in the truth table is

(a)

9

(b)

8

(c)

6

(d)

3

3. Which one is the contrapositive of the statement (pVq)⟶r?

(a)

ㄱr➝(ㄱp∧ㄱq)

(b)

ㄱr⟶(p∨q)

(c)

r⟶(p∧q)

(d)

p⟶(q∨r)

4. The proposition p ∧ (¬p ∨ q) is

(a)

a tautology

(b)

(c)

logically equivalent to p ∧ q

(d)

logically equivalent to p ∨ q

5. If * is defined by a * b = a2 + b2 + ab + 1, then (2 * 3) * 2 is

(a)

20

(b)

40

(c)

400

(d)

445

6. Which of the following is a tautology?

(a)

p ν q

(b)

p ៱ q

(c)

q v ~ q

(d)

q ៱ ~ q

7. The number whose multiplication universe does not exist in C.

(a)

0

(b)

1

(c)

0

(d)

1

8. If p is true and q is unknown, then _________

(a)

~ p is true

(b)

p v (~p) is false

(c)

p ∧ (~p) is true

(d)

p v q is true

9. In (N, *), x * y = max(x, y), x, y $\in$ N then 7 * (-7)

(a)

7

(b)

-7

(c)

0

(d)

-49

10. The number of commutative binary operations which can be defined on a set containing n elements is

(a)

n$\frac { n(n+1) }{ 2 }$

(b)

${ n }^{ { n }^{ 2 } }$

(c)

$n^{ \frac { n }{ 2 } }$

(d)

n2