Number of pieces into which the cake has been cut = 8
Number of people that ate all the pieces = 6
Let us assume the division in which the cake has been divided for everyone to have an equal amount = x
Then
6x = 8
x = 8/6
= 4/3
= 1 1/3
So it can seen that the cake has been divided in such a way that each part of the cake was 1 1/3. I hope the procedure is clear enough for you to understand.