Electricity - Calculating currents & Voltages etc

I am currently studying a HNC in Engineering and I am stuck on what is a simple electricity question but I'm getting myself confused.
I have a circuit with a 45v battery (E1) in series with a 3ohm resistor (R1), with a 30v battery (E2) and 6ohm resistor (R2) in parallel and then a 3ohm resistor (R3) in parallel to that.

I need to calculate the following:

Current through R1
Voltage across R1
Current through R2
Voltage across R2
Power dissipated in R3

Please could someone explain these to me? I have got 3 different answers to part one and I'm not sure which is correct.

Thanks