Answer:
gcf of 15, 18, 30 = 3
Step-by-step explanation:
Greatest common factor: the positive integer that divides the given numbers with no remainder, that is, where the quotient is also a positive integer.
Factors of 15: 1, 3, 5, 15
1x15 = 15
3x5 = 15
Factors of 18: 1, 2, 3, 6, 9, 18
1x18 = 18
2x9 = 18
3x6 = 18
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
1x30 = 30
2x15 = 30
3x10 = 30
5x6 = 30
gcf of 15, 18, 30 = 3, as seen in the list of factors of the three numbers given.
This is because 3 is the greatest positive integer that divides 15, 18 and 30 without any remaining or obtaining a positive integer quotient.
Hope this helps!