Question

A set of two frames with square openings when perfectly overlapped allow light through in certain patterns. Four sets are shown: frames are either hinged (A, B) or pivoted (C, D). The red frame is fixed and the blue frame is movable. Which option(s) will allow the light to pass through as shown in the target pattern?

• A. A
• B. B
• C. C
• D. D

Hint:

In frame-overlay puzzles, visualize movement type (hinge vs pivot). Pivot gives more flexibility for diagonal matches, while hinge is limited to rotation about one side.

Answer 1

The Correct Option is B, D

Step 1: Observe the target pattern.
The final pattern has 5 square openings arranged asymmetrically.
Step 2: Check option A.
Hinge arrangement does not produce the target alignment of 5 squares. ⇒ Not correct.
Step 3: Check option B.
When the blue frame is rotated on the hinge, the openings align to produce exactly the target pattern. ⇒ Correct.
Step 4: Check option C.
Pivot arrangement fails to align all openings to match the target. ⇒ Incorrect.
Step 5: Check option D.
With pivot adjustment, the openings align exactly with the required pattern. ⇒ Correct.
Step 6: Conclude.
Options B and D are correct. Final Answer: \[ \boxed{\text{B and D}} \]