Question

what is the highest common factor of 38,95,171

Answer 1

1. Decompose all numbers into prime factors

38 2 19 19 1 95 5 19 19 1 171 3 57 3 19 19 1

2. Write all numbers as the product of its prime factors

Prime factors of 38 = 2 . 19

Prime factors of 95 = 5 . 19

Prime factors of 171 = 32 . 19

3. Choose the common prime factors with the lowest exponent

Common prime factors: 19

Common prime factors with the lowest exponent: 191

4. Calculate the Highest Common Factor or HCF

Remember, to find the HCF of several numbers you must multiply the common prime factors with the lowest exponent.

HCF = 191 = 19