\(4+10=\frac{2 V _{0}}{5}+\frac{ V _{0}}{2}\)
\(14=\frac{4 V _{0}+5 V _{0}}{10}\)
\(V _{0}=\frac{140}{9} Volt \)
Potential difference across \(2 \Omega\) resistor is \(20- V _{0}\)
That is \(\left(20-\frac{140}{9}\right)\) Volt
Hence answer is \(\left(\frac{40}{9}\right)\) Volt