Ok so you have 50mL of sucrose and 977mL of buffer solution - after equilibrium the concentration of sucrose is 0.48M - what is the concentration before hand?

How do you do this??

I don't understand the problem. Not at all. Why do we need a buffer with sucrose. Is the 50 mL added to the 977 mL? What is the final volume (since volumes are not additive usually).