Answer:
3
Explanation:
Let's write the factors:
48's factors are = 1, 2, 3, 4, 6, 8, 12, 16, 24 and 48.
24's factors are = 1, 2, 3, 4, 6, 8, 12, 24.
45's factors are =1, 3, 5, 9, 15 and 45.
The greatest number that is in all three of these lists of factors is 3!
So, 3 is the greatest common factor between all three numbers!