Question

how wefind combined resistance in parallel resistors

Answer 1

here is your answer OK

Calculate the voltage drop of a current across a resistor using Ohm's law. Contrast the way total resistance is calculated for resistors in series and in parallel. Explain why total resistance of a parallel circuit is less than the smallest resistance of any of the resistors in that circuit.

Answer 2

Let the combined resistance be R'
let the resistors be R1,R2 etc...
1/R'=1/R1+1/R2+etc...