Help with this problem (circuits)?

It is a series circuit. The emf of e1 (150V) is reduced by the emf of e2 (50V) so the overall emf is 100V. This goes through two resistors which add to 5 ohms. The resulting current is 100 / 5 or 20 Amps. If the voltage on the high side of e2 is 50V, and the emf of e2 is 50 volts, then the potential on the low side of e2 is (50 - 50) or zero volts. The twenty amps through R1 makes a drop of 20 amps X 3 ohms or 60 volts. Zero minus 60 results in a voltage at Q of minus 60 volts.