A current of 0.5 A flows in a 60 W light bulb when the voltage differences between the ends of the filament is 120 V. What is the resistance of the filament?

Resistance = (voltage) / (current)

Resistance = (120 V) / (0.5 A)

Resistance = 240 ohms

Know what? There might be too much information given in this question. I want to check, because it's possible that it might not even all fit together.

To calculate my answer, I only used the voltage and the current. I didn't use the "60 watts", and I'm curious to know whether it even fits with the given voltage and current.

Power = (voltage) times (current).

Power = (120 V) times (0.5 A)

Power = 60 watts

Well gadzooks and sure enough! The three numbers given in the question all go together nicely.

And not only THAT!

The answer could have been calculated by using ANY TWO of them.