RRB NTPC - Number System Online Test (MCQ Quiz)

1. Which of the following is a natural number?

A) 0 B) -5 C) 10 D) 3.14

2. The sum of two prime numbers is always:

A) Prime B) Even C) Odd D) Composite

3. Which of the following is the smallest prime number?

A) 0 B) 1 C) 2 D) 3

4. The product of a non-zero rational number and an irrational number is always:

A) Rational B) Irrational C) Integer D) Zero

5. Which number system has only two digits, 0 and 1?

A) Decimal B) Binary C) Octal D) Hexadecimal

6. What is the value of 0! (zero factorial)?

A) 0 B) 1 C) Undefined D) Infinity

7. The set of all integers is denoted by which symbol?

A) N B) Q C) Z D) R

8. Which of the following is an even number?

A) 17 B) 23 C) 36 D) 41

9. The sum of all natural numbers from 1 to 10 is:

A) 45 B) 50 C) 55 D) 60

10. What is the reciprocal of 5?

A) 1/5 B) -5 C) 0.2 D) Both 1/5 and 0.2

11. Which of the following is a composite number?

A) 2 B) 3 C) 4 D) 5

12. The number that can be expressed in the form p/q, where p and q are integers and q is not zero, is called a:

A) Irrational number B) Integer C) Rational number D) Natural number

13. What is the largest prime number less than 50?

A) 43 B) 47 C) 49 D) 51

14. Which of the following is an odd number?

A) 100 B) 204 C) 315 D) 408

15. The set of all rational numbers is denoted by which symbol?

A) N B) Z C) R D) Q

16. Which number is neither prime nor composite?

A) 0 B) 1 C) 2 D) 4

17. What is the sum of the first five even natural numbers?

A) 20 B) 25 C) 30 D) 35

18. The number pi (π) is an example of a:

A) Rational number B) Integer C) Irrational number D) Prime number

19. Which of the following is the smallest natural number?

A) 0 B) 1 C) 2 D) None of the above

20. The product of two prime numbers is always:

A) Prime B) Even C) Odd D) Composite

21. Which number system uses 16 distinct symbols?

A) Binary B) Octal C) Decimal D) Hexadecimal

22. What is the additive inverse of -7?

A) 7 B) -7 C) 1/7 D) 0

23. Which of the following is a perfect square?

A) 10 B) 16 C) 20 D) 250

24. The set of all real numbers is denoted by which symbol?

A) Q B) Z C) R D) C

25. What is the largest prime number less than 30?

A) 23 B) 29 C) 27 D) 31

26. Which of the following is a terminating decimal?

A) 1/3 B) 1/7 C) 1/4 D) 1/9

27. The number 0 is classified as:

A) Natural number B) Prime number C) Composite number D) Even number

28. What is the multiplicative inverse of 3/4?

A) 4/3 B) -3/4 C) 3/4 D) 1

29. Which of the following is a twin prime pair?

A) (2, 3) B) (5, 7) C) (7, 11) D) (11, 13)

30. The sum of the first 'n' natural numbers is given by the formula:

A) n(n+1) B) n(n-1)/2 C) n(n+1)/2 D) (n+1)(n+2)/2

31. Which of the following numbers is divisible by 3?

A) 1234 B) 5678 C) 9876 D) 1111

32. What is the smallest composite number?

A) 1 B) 2 C) 3 D) 4

33. Which number system is commonly used in computers?

A) Decimal B) Octal C) Binary D) Hexadecimal

34. The number that cannot be expressed in the form p/q is called a:

A) Rational number B) Integer C) Irrational number D) Whole number

35. What is the value of 5! (5 factorial)?

A) 15 B) 25 C) 60 D) 120

36. Which of the following is an integer?

A) 1/2 B) 3.14 C) -10 D) √2

37. The sum of an even number and an odd number is always:

A) Even B) Odd C) Prime D) Composite

38. Which of the following is divisible by 5?

A) 1234 B) 5670 C) 9876 D) 1112

39. What is the largest two-digit prime number?

A) 91 B) 97 C) 93 D) 99

40. The number system with base 8 is called:

A) Decimal B) Binary C) Octal D) Hexadecimal

41. Which of the following is a non-terminating, repeating decimal?

A) 1/2 B) 3/4 C) 2/5 D) 1/3

42. The sum of two odd numbers is always:

A) Odd B) Even C) Prime D) Composite

43. Which number is the identity element for addition in the set of integers?

A) 1 B) -1 C) 0 D) Undefined

44. What is the smallest prime number greater than 100?

A) 101 B) 103 C) 107 D) 109

45. The number that can be expressed as a fraction p/q where q = 0 is:

A) Rational B) Irrational C) Undefined D) Integer

46. Which of the following is a rational number?

A) π B) e C) √2 D) 22/7

47. What is the product of the first three odd prime numbers?

A) 15 B) 35 C) 45 D) 105

48. The set of all natural numbers is denoted by which symbol?

A) Z B) Q C) R D) N

49. Which of the following is a property of prime numbers?

A) They are always odd. B) They have exactly two distinct positive divisors. C) They are always divisible by 3. D) They are always less than 100.

50. What is the number of integers between -5 and 5 (exclusive)?

A) 9 B) 10 C) 8 D) 7

Number System - Online Test

Test Results