To find this you first have to identify the prime factors of each number. In this case they are:
15 = 3x5
51 = 3x17
The next step is to identify any common prime factors. In this case both numbers have a 3 as a prime factor. Therefore the HCF of 15 and 51 is 3.
3.
No. The hcf of 51 and 64 is 1.
The GCF/HCF of 17 and 51 is 17.
3 is the hcf
The HCF is one
It is 1 but the HCF is 3
It is 1 but the HCF is 3
The common factors are: 1, 3, 17, 51
The Highest Common Factor (HCF) of the two numbers is 3. 63/3 = 23 and 51/3 = 17.
51/66 = 17/22 in its lowest terms by dividing the numerator and the denominator by 3 which is their HCF
45
150.