Tricky Test 2 Level 67

Overview

• Difficulty: Regular
• Estimated moves: 4

Three identical-looking light bulbs hang from wires, labeled A, B, and C on circular buttons beneath them. All three bulbs glow the same warm yellow-orange color, so you cannot tell which has been lit longest by sight alone. The prompt asks "Which light bulb has been on for more than 3 minutes?" The puzzle is a physics riddle: a bulb that has been on for several minutes gets hot, and the only way to detect that is to touch it.

Step-by-Step Solution

1. Observe that bulbs A, B, and C are visually identical in brightness and color, so guessing A or C randomly will cost you a heart.
2. Press and hold your finger on bulb A to "feel" its temperature. Nothing special happens.
3. Press and hold your finger on bulb C as well. Again, it feels cool.
4. Finally, press and hold on bulb B (the middle bulb). This one has been on the longest and is hot to the touch.
5. Select/tap bulb B. The level completes, confirming that the middle bulb is the one that has been on for more than three minutes.

Strategy & Reasoning

The visual design deliberately hides the answer: every bulb is lit the same color, so there is no brightness or color clue. The physics insight is that an incandescent bulb heats up while it is on; a bulb that has been burning for more than three minutes is noticeably warm, while one that was just switched on is still cool. The game simulates this by reacting when you touch the correct bulb. The reason the video touches A and C first is that you have to eliminate them before you know B is the hot one. There is no on-screen label telling you the temperature — you literally have to "touch and feel" each bulb.

Each bulb hangs from its own wire with a grey screw base. The three circular buttons beneath them are labeled A, B, and C. The game does not display any thermometer, and the bulbs do not change color when touched, so the only feedback is the level completing once you select the hot bulb. The reasoning mirrors the classic riddle of identifying which switched-on bulb is warm: heat, not light, is the tell. The middle bulb has been burning longest, so it is the hottest.

You can touch A and C first to rule them out; they will simply not trigger anything. Then touch B, and the game accepts your selection. There is no need to long-press; a tap-hold on each bulb is enough to sample its temperature. The three bulbs are physically identical in size and glow intensity, which is the whole point of the riddle. The hint after solving confirms the middle bulb was the one on longest.

Tips & Common Mistakes

• Guessing based on brightness. All three bulbs are intentionally drawn at the same brightness, so visual inspection gives no answer.
• Tapping only one bulb. You cannot know which is hot until you test them; touch A and C to rule them out, then B.
• Choosing A or C. The correct answer is the middle bulb, B.
• Expecting a color change. The bulb does not visibly turn red; the confirmation comes from selecting B after testing.