Answer:
30
Explanation:
Factors of 150 = 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75, 150.
Factors of 180 = 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90.
The greatest common factor of 150 and 180 is 30, because 30 is the highest number that is divisible by both numbers.