A $10\;V$ battery with internal resistance $1V$ and a $15V$ battery with internal resistance $0.6V$ are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to :

Question

$\begin{array}{1 1} 11.9\;V \\ 12.5\;V \\ 13.1\;V \\ 24.5\;V \end{array} $