I messed up, but I should be able to answer now. Light one lamp and wait for 5 minutes. Then turn it off, turn on another one, and go upstairs. The first lamp will be warm, the second will be lit, and the third will not be lit.
I messed up, but I should be able to answer now. Light one lamp and wait for 5 minutes. Then turn it off, turn on another one, and go upstairs. The first lamp will be warm, the second will be lit, and the third will not be lit.