A 20.2 mL solution of HBr (a strong acid) of unknown concentration was titrated using 0.2406 mol L^-1 NaOH using phenolphthalein as a pH indicator. At the moment when the solution turned a consistent light pink colour, the burette volume read 25.33 mL. The initial burette reading before the experiment was 7.24 mL. What was the concentration of HBr in the original HBr solution in mol L^-1 ?