What is the greatest common factor of 84 and 231?

Answer 1

Use the Euclidean Algorithm to find gcf

231 = 84*2 + 63

84 = 63*1 + 21

63 = 21*3

Therefore 21 is the greatest common factor of 84 and 231.

For the Euclidean Algorithm you take the larger of the 2 numbers and find how many times the the second number can fit in to it. Then use the second number and see how many times the remainder goes in to it. When you get to a point where there is no remainder then you have found the gcf. It is the last remainder that you calculated.