In the circuit shown in Fig the current through the 12.0-V batte

In the circuit shown in Fig the current through the 12.0-V battery is measured to be 70.6 mA in the direction shown. What is the terminal voltage V ab of the 24.0-V battery?

70.6 mA 20.0 Ω + 24.0 V 12.0 V 30.0 Ω3 10.0 Ω 10.0 Ω