A complex of cobalt with ammonia is analyzed for determining its formula, by titrating it against a strandarized acid as follows :
 $\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_{\mathrm{x}}{\mathrm{Cl}}_{\mathrm{y}}\left(\mathrm{aq}\right)+\mathrm{HCl}\to {\mathrm{NH}}_4^{+}\left(\mathrm{aq}\right)+{\mathrm{Co}}^{\mathrm{y}+}+\left(\mathrm{aq}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)$  A 1.8 g complex required 20.00 mL 1.54 M HCl to reach the equivalence point. Also, if the reaction mixture at equivalence point is treated with excess of AgNO₃  solution, 7.735 g of AgCl precipitate was produced. What is the formula of this complex?
[Given: atomic weight of CO = 59 gmol^-1]