# Find the total resistance of circuit with both series and parallel resistors

I found this circuit in a textbook, but I'm having a difficult time calculating the total resistance here. I tried using the formula for parallel resistors with the 3 resistors the the upper left, and then add that to the most right resistors. This would give me the total resistance of the upper half of the circuit. I then used that resistance, and used the formula for parallel circuits with the lower portion, but that gave me an incorrect answer.

The solution is supposedly 10ohm / 11. • This is recognizable as an application of a delta /wye transformation – placeholder Jun 6 '16 at 9:38
• @placeholder it can be done still simpler by series/parallel transformations. R is 1 ohm. – Roger C. Jun 6 '16 at 9:42
• @RogerC. you're no fun ... ;) – placeholder Jun 6 '16 at 9:47
• @placeholder ok, I got it ;-) – Roger C. Jun 6 '16 at 12:57

If R=1, your approach is correct.

1. 1 // 2 = 23

2. 23 + 1 = 53

3. 53 // 2 = 1011

1. simulate this circuit – Schematic created using CircuitLab

2. simulate this circuit