Difficulty: Easy
Correct Answer: C and E
Explanation:
Introduction / Context:We are given two chains that must be merged into a single left-to-right order. The task is to identify the extreme-left and extreme-right persons.
Given Data / Assumptions:
Concept / Approach:Merge the two constraints by overlapping the shared person B and preserving order on each side. The combined consistent sequence becomes C – A – B – D – E.
Step-by-Step Solution:
Start with C – A – B from the first rule.Append D to the right of B and E to the right of D to satisfy the second rule.The final arrangement is C (leftmost), A, B, D, E (rightmost).Verification / Alternative check:Any reordering that changes the relative positions (e.g., placing D left of B or A right of B) will violate at least one rule.
Why Other Options Are Wrong:Pairs that do not include C on the far left or E on the far right contradict the merged chain.
Common Pitfalls:Misreading “left of” and “right of” or trying to place D to the left of B.
Final Answer:C and E
Discussion & Comments