Finding the HCF using Prime Factorisation

Find the HCF of
10 and 15.

• 5

• 12

• 3

• 8

Answer explanation

The highest common factor (HCF) of 10 and 15 is 5, which is the correct choice. It is the largest number that divides both 10 and 15 without leaving a remainder.

Find the HCF of
68 and 51.

• 12
• 25
• 30
• 17

Find the HCF of
98 and 70.

• 20
• 35
• 14
• 10

Find the HCF of
280 and 105.

• 70
• 45
• 20
• 35

Find the HCF of
168 and 210.

• 42
• 90
• 72
• 56

Find the HCF of
44 and 33.

• 22
• 15
• 9
• 11

Find the HCF of
5 and 6.

• 1
• 4
• 3
• 2

Find the HCF of
86 and 172.

• 172
• 86
• 43
• 86

Find the HCF of
62 and 186.

• 10
• 2
• 3
• 25