A tourist takes his 21 W, 120 V AC razor to Europe, finds a special adapter, and plugs it into 220 V AC. What power does the razor consume as it goes up in smoke? P=IV=deltaVsquared/R attempt at solution: I used P=IV for 120 V to find the current, and using that number, plugged the numbers into the equation for 220V. The hint for the problem says that the resistance doesn't change for the razor in Europe... but I don't know how that helps. I feel like I'm missing something very easy but I'm stuck.