Sarah Chen had cleared every physical challenge at the Riverside Fire Department—climbing ladders carrying hoses, and simulating rescues. But as she waited in the plain white room at headquarters, she realized this last test would check something quite different: how well she could think under pressure.
Chief Martinez had put it : “Battling fires means making smart choices with limited information when people’s lives hang in the balance.”
Now looking at three identical electrical switches on a bare wall, Sarah grasped why this test mattered so much. In real crises, firefighters often had to deal with unfamiliar building systems making vital choices about power, gas, and water controls without knowing all the consequences.
“This mimics a real situation,” Chief Martinez’s voice crackled over the intercom. “You’re in a building’s utility room during an emergency. In the next room, three light bulbs depict different building systems. Each switch controls one light bulb, but you don’t know which. You can flip these switches as much as you want from here, but once you open that door to the next room, there’s no turning back. So I will meet you in the next room and you need to tell me which switch controls which bulb?”
To everyone’s surprise Sarah stepped in the next room few minutes later and accurately told the Chief which bulb is operated by which switch. Can you tell how Sarah figured it out so accurately?
——— View the answer ———
Sarah found her plan—one that would ensure correct solution.
Phase 1: The Plan Setup
She turned Switch 1 ON and kept it there for 10 minutes using her watch to time. After 10 minutes, she turned Switch 1 OFF
She turned Switch 2 ON and left it that way
Switch 3 stayed OFF the whole time
Phase 2: The Check
Sarah took a deep breath and opened the door and stepped into next room. She could easily tell:
The bright light: Switch 2 controlled this system (left ON)
The dark but hot light: Switch 1 controlled this system (just turned off still hot)
The dark and cool light: Switch 3 controlled this system (never turned on)
