1. The problem statement, all variables and given/known data I have to find the equivalent resistance of that series and parallel circuit. 2. Relevant equations for resistors in parallel: 1 / R = 1 / R1 + 1 / R2 + 1 / R3 +... for resistors in series: R = R1 + R2 + R3 + ... 3. The attempt at a solution The good answer has been given, its 8,5 Ω I tried but i cant have that answer. What I made: 15Ω + 9 Ω=24 and 19Ω+5Ω=24 1/ (1/24+1/8) + 1/ (1/24) + 2 +0,2 I know, it is wrong but i cant do the right thing.