Some solutions are taken at specified concentration and have the following solution codes. Identify the four digit number abed where ab= Sum of solution codes of those solutions, which will have a significant buffer action. cd = Sum of solution codes of those solutions, which for the given amount of acid or base and salt, have maximum buffer capacity

Specification of initial concentration	Solution code
A solution having 0.2 M of ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}$ and 0.4 M of ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COONa}$	11
A solution having 0.01 M of  and 2 M of	22
A solution obtained after mixing 50 ml 0.8 M  of ${\mathrm{CH}}_3\mathrm{COOH}$ and 50 ml 0.4 M of $\mathrm{NaOH}$	33
A solution obtained after mixing 100 ml 0.4 M  of ${\mathrm{NH}}_4\mathrm{Cl}$and 50 mL 0.4 M of $\mathrm{NaOH}$	44