1. The problem statement, all variables and given/known data Determine Req, the missing I's and V's? 2. Relevant equations V=IR 3. The attempt at a solution First problem is that I thought I learned that R2 and R3 are in parallel so you have to use the recipercal rule, but looking back at my notes for Interpetation for C.E. I saw that he said that all of these are in series, as you can see this dellima will mess up my Req. So my question is, do I find Req for R2 and R3 then add those to R1 and R4 to get Req, or is it simple R1+R2+R3+R4. And why? But besides that I need to find R3 which i thought I could use V3=iR i is given as 400mA, so R3 is 10 Ohms. This doesn't look right seeing as all the other resistors are in the thousands(1kOhm=1000Ohms). Am i on the right track?