This is how engineers think: Use observation + experimentation 🔬 #EngineeringMindset #LogicPuzzle #CriticalThinking #STEMFun #iCode Answer: Turn ON switch 1 for a few minutes. Turn it OFF. Turn ON switch 2. Enter room: Bulb ON = switch 2 Bulb OFF but warm = switch 1 Bulb OFF and cold = switch 3