What is the m of acid after titration?

Suppose you dissolve 50.00mg of ascorbic acid (M=176.124g/mol) in water in a 100.0mL volumetric flask. Then you remove a 10.0mL aliquot of the solution, put it into a beaker, and add 20.00mL water and 10.00mL buffer solution. What m of ascorbic acid is in the beaker?