Answer
3
Left resistance
These three resistances are in Parallel. Their fractions are added.
- 1/4 + 1/6 + 1/12 = 1/R_left Make everything out of 12s
- 3/12 + 2/12 + 1/12 = 1/R_left Add
- 6/12 = 1/R_left Reduce
- 1/2 = 1/R_left Cross Multiply
- 1*R_left = 2 Simplify
- R_left = 2 Answer for left
Right Resistance
- 1/2 + 1/2 = 1/R_right Add reciprocals
- 2/2 = 1/R_right Simplify
- 1 = 1/R_right Multiply both sides by R_right
- R_right = 1
Answer
R_left + R_right = 2 + 1 = 3
