I'm not sure what GIF means. I will take it as Greatest Common Factor. If this is incorrect, please leave me a note.
250: 5 * 5 * 5 * 2
45: = 3 * 3 * 5
30: = 2 * 3 * 5
GCF = 5
The greatest common factor is the number found in all three of the given numbers.
