Find the equivalent resistance (detailed solution)

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 12s3/12 + 2/12 + 1/12 = 1/R_left      Add   6/12 = 1/R_left                           Reduce1/2 = 1/R_left                             Cross Multiply1*R_left = 2                                Simplify R_left = 2                                  Answer for left

Right Resistance

1/2 + 1/2 = 1/R_right                 Add reciprocals2/2 = 1/R_right                        Simplify  1 = 1/R_right                             Multiply both sides by R_rightR_right = 1

Answer

R_left + R_right = 2 + 1 = 3