Respuesta :

3 6/6  because if you make the mixed number an improper fraction it would be 24/6 and that equals to 4. I am not sure if that's correct but you could wait till others answer. ?=6 
It would be 4 = 3 and 6/6 this is because 6/6 is equal to a whole. Due to this whole, you could simply add 3 + 1 and it makes it 4!

6/6 = 1
3 + 6/6 or 1 = 4