A string of 29 identical Christmas tree lights

are connected in series to a 120 V source. The
string dissipates 65 W.
What is the equivalent resistance of the
light string?
Answer in units of Ω

2 answers

Power = 65 W = V^2/R
V = 120 V

where R is the resistance of the string. Solve for it

The number of lights is not needed.
205.7142857 ohms