The highest common factor of 12, 30, 42 and 72 is
6
To find the highest common factor (HCF) of 12, 30, 42, and 72, we will use the process of prime factorization.
Step 1: Prime factorize each number.
Prime factorization of 12: 2 × 2 × 3
Prime factorization of 30: 2 × 3 × 5
Prime factorization of 42: 2 × 3 × 7
Prime factorization of 72: 2 × 2 × 2 × 3 × 3
Step 2: Identify the common prime factors.
The common prime factors of these numbers are 2 and 3.
Step 3: Determine the lowest power of the common prime factors.
The lowest power of 2 is 2^1 = 2.
The lowest power of 3 is 3^1 = 3.
Step 4: Multiply the lowest powers of the common prime factors.
HCF = 2 × 3 = 6
Therefore, the highest common factor of 12, 30, 42, and 72 is 6.