When `Na_(2)CO_(3)` solution is titrated against HCl solution, the indicator used is

(A ) : When Na_(2)CO_(3) is titrated against HCl in presence of phenolphthalein indicator, it is converted into NaCl. (R ) : Phenolphthalein indicator shows colour change in the P^(H) range of 3.5 to 4.6

3.65gm equimole mixture of NaOH and Na_(2)CO_(3) is titrated against 0.1M HCl using phenolphathalein as an indicator, V_(1)mL of acid was required to reach end point. In another experiment 3.65gm of same mixture is titrated against 0.2M HCl using methyl orange as an indicator, V_(2)mL of acid was required to reach end point. V_(1)+V_(2) is :

Which of the following gives equivalent mass of Na_(2)CO_(3) when titrated against HCl in the presence of methyl orange ?