Hello all,

I recently took the 08 test as part of my preparation for the test in Oct and I was using tashwoods solutions to go over the test but I do not understand #68. Here is the question

The problem I am having is how to find the total resistance. Tashwoods solution says the resistor grid is composed of 3 2R resistors in parallel to give R_tot = 2R/3 and therefore the current through the battery is I = 3V/2R but why is the total resistance 2R/3? Do you ignore the two horizontal resistors for some reason? I would be eternally grateful if someone could explain this to me or provide a link (or book reference) to somewhere that goes over resistors in grids. I've googled it but have only found info on how resistors add in parallel and in series.

Thanks,

Jim