Question

One book has 84 pages. Another book has 210 pages. Which is the greatest common factor of the number of pages in the two books?.

a. 14
b. 21
c. 42
d. 84

Answer 1

C

Explanation:

Factor the two numbers into their prime factors.

84: 2 * 2 * 3 * 7

210: 2 * 5 * 3 * 7

The highest common factor is 2 * 3 * 7

The highest common factor is 42