Solutions by everydaycalculation.com

The GCF of 42 and 20 is 2.

- Find the prime factorization of 42

42 = 2 × 3 × 7 - Find the prime factorization of 20

20 = 2 × 2 × 5 - To find the GCF, multiply all the prime factors common to both numbers:

Therefore, GCF = 2

MathStep (Works offline)

Download our mobile app and learn how to find GCF of upto four numbers in your own time:

Android and iPhone/ iPad

Find hcf of: 84 & 40 21 & 10 126 & 60 210 & 100 294 & 140 84 & 20 42 & 40 126 & 20 42 & 60 210 & 20 42 & 100 294 & 20 42 & 140

Enter two numbers separate by comma. To find GCF of more than two numbers, click here.

The greatest common factor (GCF) is also known as greatest common divisor (GCD) or highest common factor (HCF).

© everydaycalculation.com