Identify the resistance of each parallel branch
Use the parallel resistance formula: 1/Rt = 1/R1 + 1/R2 + 1/R3 + …
Add the reciprocals of all branch resistances
Take the reciprocal of the sum to get total resistance
For two resistors, use: Rt = (R1 × R2) / (R1 + R2)
For identical resistors, use: Rt = R / n
Check that the final resistance is less than the smallest branch resistance