Welcome to your daily brain workout! Today’s puzzle will stretch your logical thinking. Ready?

🧩 Today’s Puzzle: The Light Bulb Riddle

You are outside a room with a closed door. Inside the room, there are three light bulbs. Outside the room, there are three switches. Each switch controls one of the bulbs. You can flip the switches however you like, but you may only open the door and enter the room ONCE. How do you determine which switch controls which bulb?

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💡 Hint

You can touch the bulbs. What property of a light bulb changes when it’s been on for a while, but doesn’t immediately disappear when you turn it off?

📅 Yesterday’s Puzzle (19 June 18) — Answer

Puzzle: The Counterfeit Coin — 12 coins, 1 counterfeit, 3 weighings.

✅ Answer: Yes, it’s possible. Weigh 4 vs 4 first. If equal, counterfeit is in the 4 unweighed — solved in 2 more weighings. If unequal, note the direction, rotate 3 coins between sides, and use the results pattern to pinpoint the counterfeit. It’s known as the ’12 Coin Problem’ and is beautifully elegant.

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