Question

If a green flag is flown on pole 5, which of the following must be true?

• A. \( \text{a green flag is flown on pole 1.} \)
• B. \( \text{a green flag is flown on pole 2.} \)
• C. \( \text{A green flag is flown on pole 7.} \)
• D. \( \text{a white flag is flown on pole 3.} \)
• E. \( \text{A white flag is flown on pole 4.} \)

Hint:

Ensure pole 3 restriction and adjacency.

Answer 1

The Correct Option is D

Step 1: Green on 5, 3 greens total, no green on 3, so remaining greens on 1, 4, 6, 7, avoiding adjacency.
Step 2: 5G next to 4 and 6, so 4 and 6 cannot be green; 1 and 7 are options, but 3 must be non-green (white or yellow).
Step 3: With 2 whites and 2 yellows, 3 cannot be yellow (yellow avoids 5), so 3 must be white to fit constraints.
Step 4: Any valid setup (e.g., 1G, 3W, 4Y, 5G, 6Y, 7G) requires 3W, making (D) must be true.