Puzzle image: made for aglena.
An arrow is spinning on a row of compass tiles. It starts pointing North, and it always turns clockwise from one tile to the next. Four tiles in, it is pointing West. Can you spot the rule and say where the arrow points on tile 5?
The puzzle
- Tile 1: the arrow points North.
- Tile 2: the arrow points North-East.
- Tile 3: the arrow points South-East.
- Tile 4: the arrow points West.
Which way will the arrow point on tile 5? Is it A (North), B (East), C (South-West) or D (North-West)?
Show hint
Look at how far the arrow turns each time, not where it ends up. Count the turns in 45° steps, the gap between two neighbouring compass points.
Show answer
Answer: B, East.
Puzzle image: made for aglena.
- Measure each heading clockwise from North: North is 0°, North-East is 45°, South-East is 135° and West is 270°.
- Now look at the turns between tiles: 0° to 45° is +45°, 45° to 135° is +90°, and 135° to 270° is +135°.
- Each turn is 45° bigger than the last, so the next turn is +180°, a half turn.
- 270° + 180° = 450°. Take away one full 360° turn and you are left with 90°, which is East.
The trap is assuming the turn stays the same size. Repeat the last turn of 135° and you land on North-East, which isn’t even an option. If you think it only ever moves one compass point (45°) at a time, you pick North-West (D), and if you take the turn to be a steady 90° you get North (A). The arrow’s position looks random; the size of the turn is what follows the pattern.
