Voldie: You are shitting me. Look, here is another experiment, this time with ten light bulbs, now we have three light bulbs not lit up. Therefore, the voltage is 250*(7/10) = 161 V. Hm, we apparently have a very unstable power here. Let me talk to the facilities guys (runs away). (strolls back) Okay, they told me to try again: the flux capacitor was overloaded. (quickly reshuffles the light bulb). Look, four out of ten light bulbs are not ligthing up. 138 V again, hooray!