Respuesta :

The third number is 8 u multiply 3 and 13 which equals 39 divide 312 by 39 which equals 8
texaschic101
3 * 13 * x = 312
39 * x = 312.....divide both sides by 39
x = 312 / 39
x = 8

lets check...
3 * 13 * 8 = 312
312 = 312 (correct)

ur answer is 8