You calculate the equivalent thevenin equivalent resistance of the circuit. Then multiply the current times this equivalent resistance to get the voltage.
If you don't know how to find the thevenin equivalent, just Google thevenin.
Why do kids come here from a 3rd world country and ask extremely simple questions about the basics of electronics?
Why don't they learn the basics from their teachers, from text books or from Google?
The OP appears to be enrolled in the City College of San Francisco's Online Learning System. I'm gobsmacked.
He's also playing Pokemon online, gotta have your priorities.
The OP acts like a little kid in a 3rd world country. If he acts like that in a job then he will soon be fired (unless the job is about silly computer games).