Note: this isn't an actual problem from a textbook; it is something that I've been wondering about because I was never taught how to do this in school or in my physics textbook. 1. The problem statement, all variables and given/known data In this very basic circuit, how do you determine the direction and value of current through each resistor and through the vertical connection between the two parallel branches? 3. The attempt at a solution If it weren't for the connection between the two branches, you would combine each series pair of resistors, and then use I=V/R to determine the current through each branch. But when the parallel branches are connected like this, how do you determine current direction and value? Thanks.