250, 45, and 30 have a common factor of 5 because that's the only number besides 1 that all three number are divisible by. 375, 66, and 33 are all divisible by 3 so the common factor of these numbers is 3. finally, 76, 21, and 14 have no common factors other than 1; but 76 and 14 are divisible by 2, while 21 is divisible by 3, and 21 and 14 are divisible by 7.
Hope this helps!
