GCD (24,20)IS 4. sINCE gcd (4,12) IS 4, THEN gcd (24,20,12) is 4.

use this approach and the euclidean algorithim to find the GCD ( 722, 2413,209)
WHAT IS THE gcd?

GCD(722,2413) = 19

then GCD(19,209) = 19

so GCD(722,2413,209) = 19