Factors and Multiples Quiz

Which of the following numbers is not a factor of 144?

• 8

• 12

• 28

• 36

Answer explanation

To determine which number is not a factor of 144, we check each option. 8, 12, and 36 are factors of 144, but 28 is not, as 144 divided by 28 does not yield a whole number.

Which of the following numbers is not a prime factor of 462?

• 3

• 7

• 11

• 13

Answer explanation

To find the prime factors of 462, we can divide it by prime numbers. 462 is divisible by 2, 3, 7, and 11, but not by 13. Therefore, 13 is not a prime factor of 462.

3 is a factor of x while x is a factor of 126. What is the possible value of x?

• 4

• 8

• 14

• 21

Answer explanation

Since 3 is a factor of x, x must be a multiple of 3. The factors of 126 are 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, and 126. Among the choices, only 21 is a multiple of 3 and a factor of 126.

How many factors are there for 15?

• 2

• 3

• 4

• 5

Answer explanation

The factors of 15 are 1, 3, 5, and 15. Counting these gives us a total of 4 factors. Therefore, the correct answer is 4.

56 and 120 are multiples of

• 6

• 8

• 7

• 12

Answer explanation

56 and 120 are both divisible by 7. For 56, 56 ÷ 7 = 8, and for 120, 120 ÷ 7 = 17.14 (not an integer). Thus, they are not multiples of 6, 8, or 12, making 7 the correct choice.

Find the lowest common multiple (LCM) of 4,6, and 9.

• 18

• 36

• 54

• 72

Answer explanation

To find the LCM of 4, 6, and 9, we can use their prime factorizations: 4 = 2^2, 6 = 2^1 * 3^1, and 9 = 3^2. The LCM takes the highest power of each prime: 2^2 and 3^2. Thus, LCM = 2^2 * 3^2 = 4 * 9 = 36.

Calculate the sum of the lowest common multiple (LCM) and highes common factor (HCF) of 8,12 and 16.

• 40

• 44

• 52

• 56

Answer explanation

The LCM of 8, 12, and 16 is 48, and the HCF is 4. Their sum is 48 + 4 = 52, which matches the correct answer choice.