LCM and HCF

Which of the following numbers has 21 as a factor?

• 43

• 63

• 83

• 103

Which of the following lists all the factors of the number 46?

• 1, 2, 3, 46

• 1, 3, 4, 46

• 1, 4, 13, 46

• 1, 2, 23, 46

3 is a factor of x. x is a factor of 63. The possible value of x is

• 6

• 7

• 9

• 12

Which of the following is a prime number?

• 19

• 39

• 49

• 69

Which of the following is a prime factor of the number 50?

• 1

• 3

• 5

• 10

The first three prime numbers which are greater than 20 are

• 21, 23, 29

• 23, 27, 29

• 23, 29, 31

• 27, 29, 31

Which of the following shows the prime factorization of 232?

• 1 × 232

• 4 × 58

• 2 × 2 × 2 × 29

• 1 × 2 × 2 × 2 × 29

Which of the following is a common factor of 17 and 51?

• 3

• 17

• 19

• 23

Which of the following sets of numbers have a common factor of 7?

• 12, 28, 34

• 14, 30, 47

• 16, 29, 35

• 21, 49, 84

What is the greatest number that can divide 18, 54 and 63 without leaving any remainder?

• 2

• 3

• 6

• 9