A binary $\text{AB}$ liquid mixture containing $30 \: \mathrm{~mol} \% \: \text{A}$ is subjected to differential (Rayleigh) distillation at atmospheric pressure in order to recover $60 \: \mathrm{~mol} \: \% \text{A}$ in the distillate. Assuming a constant relative volatility $\alpha_{A B}=2.2$, the average composition of the collected distillate is $\_\_\_\_\_ \: \mathrm{mol} \% \: \text{A}$ (rounded off to nearest integer).
