the answer is 5 days because....
you need to find a common multiple for the denominator for 1/8 & 3/4. so 2.
and whatever you do to the bottom you do to the top so 1 3X 2 6
- - = -
8 4 X 2 8
So 6/8 to to 1/8 is 5/8 so it will be 5 days
sorry its confusing i hope it helps