Name all 3 Wattage formulas for Ohm's Law

P=ExI   (Wattage = Volts x Amps)

P=RxI²   (Wattage = Ohms x Amps²)

P=E²÷R   (Wattage = Volts² ÷ Ohms)

Name all 3 Voltage formulas for Ohm's Law

E=RxI   (Volts = Ohms x Amps)

E=P÷I    (Volts = Watts ÷ Amps)

E=√PxR   (Volts = √Volts x Watts)

Name all 3 Resistance formulas for Ohm's Law

R=E÷I   (Ohms = Volts ÷  Amps)

R=P÷I²    (Ohms = Watts ÷ Amps²)

R=E²÷P   (Ohms = Volts² ÷ Watts)

Name all 3 Amperage formulas for Ohm's Law

I=E÷R   (Amps = Volts ÷ Ohms)

I=P÷E   (Amps = Watts ÷ Volts)

I=√P÷R   (Amps = √Watts ÷ Ohms)

You have three resistors wired in parallel in a circuit.  They are 2, 4 and 6 ohms. 

What resistance does that part of the circuit have?

1.09

Turn them all into fractions, find a common denominator, Add the fractions together. Invert the fraction back over and simplify.

You have three resistors wired in parallel in a circuit.  They are all 9 ohms each.

What is the resistance of the circuit?

3

Take the resistance of one of the resistors and divide it by the number of resistors.