What is the greatest common factor of 21 30 and 35?

Answer 1

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

The factors of 21 are 1, 3, 7, and 21.

The factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30.

The factors of 35 are 1, 5, 7, and 35.

There is only one common factor: 1. Therefore, the greatest common factor is 1.

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

The prime factors of 21 are 3 and 7.

The prime factors of 30 are 2, 3, and 5.

The prime factors of 35 are 5 and 7.

There are no prime factors in common, so the greatest common factor is 1.