There are 3 switches outside a room, 3 bulbs inside. You may enter the room only once. How do you identify which switch controls which bulb?
A
Flip switches randomly and guess
B
Turn on #1 for 10 mins, off, turn on #2, enter — warm dark = #1, lit = #2, cold dark = #3
C
You can't solve it in one visit
D
Flip them quickly in sequence
💡 Correct Answer:
Turn on #1 for 10 mins, off, turn on #2, enter — warm dark = #1, lit = #2, cold dark = #3
ℹ️ Explanation:
Heat is the hidden dimension. Bulb #1 was on long enough to warm up (but now off). Bulb #2 is lit. Bulb #3 was never touched (cold). Three facts from one visit.