40 mL of a mixture of `Na_(2)CO_(3)` and NaOH when titrated against `N//10` HCl, the end point with phenolphthalein was reached at 25 mL of HCl and at this stage methyl orange was added, the quantity of acid further required for second end point was 5 mL. Calculate the amount of `Na_(2)CO_(3)` and NaOH in `g//L` of the solution.