Solution
= Solution
For the mixed pair, $M=11.4M_\odot$ and $\mu=(14/11.4)M_\odot=1.228M_\odot$. The prescribed instantaneous <orbital decay timescale> gives
$$
\boxed{A_{\max}=5.53\times10^9\ \mathrm m,\qquad P_{\max}=18.4\ \mathrm h}.
$$
The integrated ten-billion-year merger criterion instead gives $26.6$ h. Both are pre-disruption circular-orbit estimates; the final contact/capture process differs from that for two <neutron stars>.