Respuesta :

I think it might be 4

the greatest common factor of 40 and 48 is 8.

the factors of 40 are: 1, 2, 4, 5, / 8 /, 10, 20, 40

the factors of 48 are: 1, 2, 3, 4, 6, / 8 /, 12, 16, 24, 48