1, 2, and 4
28 over 16 would be: 28/16 = 7/4
1, 2, 4, 7, 8, 14, 16, 28, 56, 112.
2 goes evenly into 4 and 28
28 goes into 7 and 2, while 30 goes into 15 and 2.
2
One.
3 with remainder 16.
7 10 16 28
The highest common factor of both number is 28
16 + 12 = 28
The number is 1.