Playing With Numbers

48. What is the H.C.F. two consecutive odd numbers?

• (A) 1 
• (B) 2 
• (C) 4 
• (D) 8

47. Which of the following is smallest prime number?

• (A) 1 
• (B) 2 
• (C) 3 
• (D) 4

46. The smallest composite number is

• (A) 1 
• (B) 2 
• (C) 3 
• (D) 4

45. The only prime number which is also even is

• (A) 1 
• (B) 2 
• (C) 4           
• (D) 6

44. Which of following number is multiple of 8?

• (A) 2 
• (B) 4 
• (C) 10         
• (D) 16

43. What is the H.C.F. of 18 and 48?

• (A) 2 
• (B) 4 
• (C) 6 
• (D) 8

42. Which of the following pair is co-prime?

• (A) 6 and 8 
• (B) 18 and 35
• (C) 7 and 35        
• (D) 30 and 415

41. Which number is neither prime nor composite?

• (A) 0 
• (B) 1 
• (C) 2 
• (D) 3

40. Common factor(s) of 15 and 25 are

• (A) 15
• (B) 25         
• (C) 5 
• (D) 75

39. The exact divisor of number 9 is

• (A) 2 
• (B) 3 
• (C) 4 
• (D) 5

38. The product of three consecutive numbers is always divisible by

• (A) 2 
• (B) 4 
• (C) 6 
• (D) 8

37. The sum of two consecutive odd numbers is always divisible by

• (A) 2 
• (B) 4 
• (C) 6 
• (D) 8

36. What are the prime factors of greatest four-digit number

• (A) 3 × 3 × 11 × 101       
• (B) 9 × 11 × 101   
• (C) 3 × 33 × 101   
• (D) 3 × 3 × 11 × 11

35. Which of the following expressions represent the prime factorisation of the numbers?

• (A) 24 = 2 × 3 × 4 
• (B) 56 = 7 × 2 × 2 × 2     
• (C) 70 = 2 × 5 × 7 
• (D) 54 = 2 × 3 × 9

34. Which of the following numbers has 4 different prime factors?

• (A) 24
• (B) 120       
• (C) 210       
• (D) 100

33. Which of the following pairs is not co-prime?

• (A) 8, 10
• (B) 11, 12
• (C) 1, 3
• (D) 31, 33