Question

What are the HCF of 90 and 66

Answer 1

HCF = 6

Explanation:

to find the HCF ( highest common factor ) of 90 and 66

First find the prime factors of each number , using prime factorisation

Next, identify the prime factors that both numbers have in common and multiply them.

90 = 2 × 3 × 3 × 5

66 = 2 × 3 × 11

here 2 and 3 are common factors, then the HCF = 2 × 3 = 6