Answer: He now has eight-fourths of the apples left.
Step-by-step explanation: If Sebastian has three whole apples and now decides to cut each apple into fourths, that is four parts, then the total number of fourths he has left can be derived as follows;
1 apple = 4 parts
3 apples = 3 x (4 parts)
3 apples = 12 parts
If Sebastian gives away four of the apples, we can now express this as;
Remainder = 12 parts - 4 parts
Remainder = 8 parts
What Sebastian had was fourths and no longer whole apples, hence from our calculation, Sebastian has eight-fourths (8 quarters, or 8 fourths) left as a fraction of his apples.