Chemistry - Ionic Equilibrium Question with Solution | TestHub

$20 \mathrm{mL}$of$0.1\mathrm{M} {\mathrm{NH}}_4\mathrm{OH}$is mixed with$40 \mathrm{mL}$of$0.05 \mathrm{M} \mathrm{HCl}$. The$\mathrm{pH}$of the mixture is nearest to:
(Given:${\mathrm{K}}_{\mathrm{b}}\left({\mathrm{NH}}_4\mathrm{OH}\right)=1\times {10}^{-5}, \log 2=0.30$,$\log 3=0.48, \log 5=0.69, \log 7=0.84$,$\log 11=1.04$)