What is the greatest common factor of 140 and 168?

Answer 1

The greatest common factor can be calculated by identifying the common prime factors and multiplying them together.

The prime factors of 140 are 2, 2, 5, and 7.

The prime factors of 168 are 2, 2, 2, 3, and 7.

The prime factors they have in common are 2, 2, and 7, so their greatest common factor is 2 x 2 x 7 = 28. Another way to approach this is to look at the difference between 140 and 168, which is 28. The greatest common factor of two numbers cannot be larger than the difference between the two numbers. Since both 140 and 168 are divisible by 28, the greatest common factor is 28.