Brain Out Level 81

Overview

The prompt "Light up the 4th bulb" shows five bulbs arranged in two rows: bulbs labeled 1, 2, 4 on the top row, and bulbs labeled 3, 5 on the bottom row. A Start button is below. The bulbs light up in sequence 1, 2, 3, 4, 5 when Start is pressed, but the sequence is fast and hard to stop at the 4th. The trick is that the 4th bulb is already labeled 4 — you can just tap it directly.

• Difficulty: Easy
• Estimated moves: 1

Step-by-Step Solution

1. Look at the bulbs. The top row has bulbs labeled 1, 2, and 4 from left to right. The bottom row has bulbs labeled 3 and 5.
2. The bulb labeled 4 is the 4th bulb by name.
3. Do not press Start. Tapping Start triggers a rapid sequence that is hard to control.
4. Simply tap the bulb labeled 4 directly. It lights up immediately.
5. The congratulations popup appears with the message "You must have been practicing a lot."

Five bulbs are labeled 1, 2, 4 on top and 3, 5 on bottom. A Start button below triggers a rapid sequence.

Do not press Start. Simply tap the bulb labeled 4 directly. It lights up immediately, and the level clears.

Tap the bulb labeled 4 directly. Do not press Start. The bulb lights up immediately. If you press Start, the sequence runs too fast to stop.

Tap the bulb labeled 4. Do not press Start. The Start button triggers a sequence that is too fast to control.

Strategy & Reasoning

The Start button is a distraction. The prompt asks for the "4th bulb," and one of the bulbs is literally labeled 4. You do not need to start the sequence and time your tap. Just tapping the bulb that is already labeled 4 lights it up. The labels 1 through 5 are printed above each bulb, making the target easy to identify. This is a "don't overcomplicate" puzzle.

The Start button triggers a rapid sequence that is hard to stop at the 4th bulb. But one of the bulbs is already labeled 4, so you can simply tap it directly. The labels are out of order on purpose (1, 2, 4 on top and 3, 5 on bottom), which makes the target easy to identify. No timing is needed.

The bulb labeled 4 is on the top row, on the right. Tap it directly. The Start button is a trap that triggers a fast sequence. No timing is needed.

Tips & Common Mistakes

• Do not press Start. The sequence runs too fast to reliably stop at the 4th.
• Do not tap the bulb in the 4th physical position. The labels are out of order on purpose.
• Do not tap bulb 1 or bulb 5. The target is the bulb labeled 4 on the top row, right side.