What is the greatest common factor of 42 and 90?

Answer 1

The GCF of 42 and 90 is 6.

One way to determine the greatest common factor is to find all the factors of the numbers and compare them.

The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42.

The factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, and 90.

The common factors are 1, 2, 3, and 6.

Therefore, the greatest common factor is 6.

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

The prime factors of 42 are 2, 3, and 7.

The prime factors of 90 are 2, 3, 3, and 5.

The prime factors in common are 2 and 3, so the greatest common factor is 2 x 3 = 6.