1. Which of the following is an irrational number?
A. 3/4
B. √2
C. 0.75
D. 1.414
Answer: B. √2
2. The decimal expansion of a rational number is always:
A. Terminating only
B. Non-terminating only
C. Either terminating or non-terminating repeating
D. Non-terminating non-repeating
Answer: C. Either terminating or non-terminating repeating
3. The square of an irrational number is:
A. Always rational
B. Always irrational
C. May be rational or irrational
D. None of these
Answer: C. May be rational or irrational
4. Which of the following numbers has a non-terminating and non-repeating decimal expansion?
A. 5.125
B. 1.41421356...
C. 3.333...
D. 7.25
Answer: B. 1.41421356...
5. √49 is:
A. Rational
B. Irrational
C. Prime
D. None of these
Answer: A. Rational
6. The number π (pi) is:
A. Rational
B. Irrational
C. Natural
D. Integer
Answer: B. Irrational
7. 2√3 is a/an:
A. Rational number
B. Irrational number
C. Integer
D. Whole number
Answer: B. Irrational number
8. The product of a rational and an irrational number is:
A. Always rational
B. Always irrational
C. May be rational or irrational
D. Zero
Answer: C. May be rational or irrational
9. Which of the following is a rational number?
A. √5
B. √9
C. √7
D. √2
Answer: B. √9
10. The number 0 is:
A. Natural number
B. Whole number
C. Rational number
D. Both B and C
Answer: D. Both B and C
11. Which of the following is not a real number?
A. 0
B. -1
C. √-2
D. π
Answer: C. √-2
12. The number 7.123456789... (non-repeating, non-terminating) is:
A. Rational
B. Irrational
C. Whole
D. Integer
Answer: B. Irrational
13. Between any two rational numbers, there are:
A. No rational numbers
B. Finite rational numbers
C. Infinite rational numbers
D. Only integers
Answer: C. Infinite rational numbers
14. Which of the following is both a rational and an integer?
A. ½
B. -4
C. √2
D. π
Answer: B. -4
15. 0.10100100010000... is an example of a:
A. Terminating decimal
B. Recurring decimal
C. Rational number
D. Irrational number
Answer: D. Irrational number
16. Which of the following sets is not closed under division?
A. Natural numbers
B. Integers
C. Rational numbers
D. Real numbers
Answer: A. Natural numbers
17. The value of (81)^0.25 is:
A. 3
B. 9
C. 27
D. 4
Answer: A. 3
(Since 81^0.25 = 81^(1/4) = 4th root of 81 = 3)
18. Which of the following is the smallest set that √7 belongs to?
A. Rational numbers
B. Integers
C. Irrational numbers
D. Natural numbers
Answer: C. Irrational numbers
19. If x = √2 and y = -√2, then x + y is:
A. 0
B. 2√2
C. -2√2
D. Undefined
Answer: A. 0
20. Which of the following numbers lies between 3 and 4?
A. √8
B. √10
C. √12
D. √15
Answer: B. √10
(Since √10 ≈ 3.16)
