The 304 was a V-8 engine built by AMC and used in some of their vehicles from 1970 to 1981.
152
Factors of 133: 1, 7, 19, 133.Factors of 304: 1, 2, 4, 8, 16, 19, 38, 76, 152, 304.GCF (133, 304) = 19
The factor pairs of 51 are (1,51) and (17,3)
The difference is between factor pairs and distinct factors. With square numbers, one of the factor pairs will be the same number twice. When listing the distinct factors, that number is only listed once.
The factor pairs of 98 are (1,98), (2,49), and (7,14).