Answer:
12
Step-by-step explanation:
One way is
divide the larger number by the smaller
If the remainder is zero then the smaller number is the greatest common factor.
If not repeat with larger number and remainder
144 ÷ 60 = 2 remainder 24 ← remainder ≠ 0
60 ÷ 24 = 2 remainder 12 ← remainder ≠ 0
24 ÷ 12 = 2 remainder zero, thus
greatest common factor is 12
