1. The problem statement, all variables and given/known data http://imageshack.us/a/img69/3384/rseistors.jpg [Broken] 2. Relevant equations Resistors in series and parallel formulas. The attempt at a solution Very confused with part (b)! So in the first square or w/e you call it (left side), R1 in series with R1 so thats 20Ω + 20Ω = 40Ω. Then the second square (middle), R2 in series with R1 so 10Ω + 20Ω = 30Ω. then 40 and 30 are in parallel 40-1 + 30-1 = 7/120-1 = 17.14Ω. But my solution Manuel has 32Ω as the resistor equivalent. I know im making a mistake somewhere but i dont know what my mistake is. help please!