Answer
$\frac{Q_H}{(Q_H)_{carnot}} = 1.625$
Work Step by Step
$\eta _{carnot} = 1- \frac{273}{773}$
$\eta_{carnot} =0.65$
But we have
$\eta = 60\% *0.65$
$\eta \approx 0.4$
Also we have $W_{carnot} = W$
$\eta_{carnot} = W_{carnot}/(Q_H)_{carnot}$
and $\eta = W/Q_H$
thus,
$\frac{\eta_{carnot}}{\eta} = \frac{Q_H}{(Q_H)_{carnot}}$
$ \frac{0.65}{0.4} = \frac{Q_H}{(Q_H)_{carnot}}$
$\frac{Q_H}{(Q_H)_{carnot}} = 1.625$
