Question

Use the prime factor method to find the greatest common factor of the group of numbers 68,170,153

Answer 1

The first step is to express each number in terms of its prime factors

Therefore,

68 = 2 * 2 * 17

170 = 2 * 5 * 17

153 = 3 * 3 * 17

We can see that the only factor that is common to the three numbers is 17

Therefore,

Highest common factor = 17