Answer
$T_H=341K$
Work Step by Step
We know that:
$\epsilon=1-|\frac{Q_L}{Q_H}|$
As in the given scenario, efficiency is related to the temperature, hence
$\epsilon=1-|\frac{T_L}{T_H}|$
This can be rearranged as:
$T_H=\frac{T_H-T_L}{\epsilon}$
We plug in the known values to obtain:
$T_H=\frac{75}{0.22}=341K$
