Calculate the \( \mathrm{pH} \) of a solution obtained by mixing \( 0.1 \) litre of \( \mathrm{p...

Calculate the \( \mathrm{pH} \) of a solution obtained by mixing \( 0.1 \) litre of \( \mathrm{pH}=4 \) and \( 0.2 \) litre of \( \mathrm{pH}=10 \). Both contain strong acid and base respectively.