How do i find the total voltage in a parallel circuit? (10 Points Best Answer)?

Okay so ive got series circuits down pact but as soon as i got to parallel circuits i got stumped on the first question. The total voltage wasnt given and the total resistance, resistor 1 and 2 and 3 were not given either. I found the total current. But i dont know where to go from here. How can i find the total voltage with that little information? Please Help. Thanks in advance