Two light bulbs are connected in series. The resistance of the filament of the first light bulb is 230Ω. The potential difference across the first light bulb is 100V and across the second light bulb,200V. What is the resistance of the second light bulb?

Answer 1

twice the voltage drop means twice the resistance

Answer 2

I = V1/R1 = 100/230 = 0.435A.
R2 = V2/I = 200/0.435 =