Enthalpy for the reaction

${\mathrm{Ag}}^{+}\left(aq\right)+{\mathrm{Br}}^{-}\left(aq\right)⟶\mathrm{AgBr}\left(s\right)\text{ is }-90\mathrm{k}J$

Magnitude of enthalpy of formation of ${\mathrm{Ag}}^{+} \left(\mathrm{aq}\right)$ and${\mathrm{Br}}^{-} \left(\mathrm{aq}\right)$ are in the ratio $5 : 6.$ Formation of ${\mathrm{Ag}}^{+}$$\left(\mathrm{aq}\right)$is an endothermic process whereas formation of ${\mathrm{Br}}^{-}$ is an exothermic process. Enthalpy of formation of $\mathrm{AgBr}$ is $-110 \mathrm{kJ}/\mathrm{mole}$. Calculate the enthalpy of formation of ${\mathrm{Ag}}^{+}\left(\mathrm{aq}\right)$ in kJ/mol