Three resistors are connected in series to a battery. If the resistances are \(R_{1}=15 \Omega, R_{2}=20 \Omega\), and \(R_{3}=25 \Omega\) and the current through the \(15-\Omega\) resistor is \(2.3 \mathrm{~A}\), what is the potential difference across the battery terminals \((a)\) if the battery is ideal and \((b)\) if the battery has an internal resistance of \(5.0 \Omega\) ?