Verified Answer :

It is 3 be cause if you do 60 3= 90
   11
3=33

so the greatest common factor is found by finding the factors and finding which ones are in both groups so exg (greatest common factor of 20 and 8 is 4 because 20:45 and 8=42 so 4 is the greastest common factor so )

90=3325
33=11
3

the greatest common factor is 3