Six friends A, B, C, D, E and F joined an institute in the year 1993, each on a different day. Only E joined after both C and D. C joined immediately before A and immediately after B, forming the consecutive sequence B, C, A. F is not the first or the last person to join, and D is not in any corner position. Who was the first person to join the institute?

Introduction / Context:
This question is a logical arrangement puzzle based on the order in which six friends joined an institute. You are given several constraints about relative joining times, including who joined consecutively, who joined after whom and which positions cannot be occupied by certain friends. From these clues you must deduce the complete order and then identify the first person who joined. Such puzzles test careful reading and multi step logical reasoning.

Given Data / Assumptions:

• Six friends A, B, C, D, E and F joined in 1993, each on a different day.
• Only E joined after both C and D, implying E is the only person later than both C and D.
• C joined immediately before A and immediately after B, so the order B, C, A appears consecutively.
• F is not the first or the last to join.
• D is not at any corner position, so D cannot be first or last.
• We must find who joined first among the six friends.

Concept / Approach:
The key idea is to treat the joining order as six positions from 1 (first) to 6 (last). The triple B, C, A must occupy three consecutive positions. Since only E joins after both C and D, E must be the last to join because anyone after D would also be after C, and only E has this property. With E fixed at position 6, we must place B, C and A in a valid block and then position D and F without violating the corner restrictions. Systematically trying possible placements for the B, C, A block leads to a unique consistent arrangement.

Step-by-Step Solution:
Label the joining days as positions 1 to 6, from first to last. Since only E joined after both C and D, E must be the only person after D and after C. This is possible only if E is at position 6, the last position. C joins immediately before A and immediately after B, so the three appear as B, C, A in consecutive positions. The triple B, C, A cannot end at position 6 because that is already taken by E. Thus the possible positions for the triple are (1, 2, 3), (2, 3, 4) or (3, 4, 5). Consider the triple at positions 3, 4, 5. Then A would be at position 5 and C at 4. For E to be after C and D, E is at 6, but D must then be before C. D would also need to avoid corners, which may be possible. However, we also know F is not first or last, and with D disallowed at 1 and 6, arranging everyone consistently becomes difficult and must be checked. A more promising placement is B, C, A at positions 1, 2, 3: position 1: B, 2: C, 3: A. With E fixed at position 6, the remaining positions 4 and 5 must be taken by D and F. D cannot be in a corner, so D must be at position 5, leaving F at position 4. We now check “only E joined after both C and D”. Here, C is at 2 and D is at 5. The only person after both C (2) and D (5) is E at position 6. No one else sits after D. Thus this arrangement satisfies all conditions. Therefore the full order is B, C, A, F, D, E, and the first person to join is B.

Verification / Alternative check:
Verify each clue in the order B (1), C (2), A (3), F (4), D (5), E (6). C is immediately after B and immediately before A, so the block B, C, A is correct. D is not at a corner, since D is at position 5. F is at position 4, not first or last. E is at position 6 and is the only person after both C (2) and D (5). Any attempt to shift the B, C, A block to positions 2, 3, 4 or 3, 4, 5 either violates the “only E after C and D” condition or forces D or F into corner positions. Hence the found order is unique and consistent.

Why Other Options Are Wrong:
E cannot be first because E must join after both C and D. D cannot be first because D is not allowed to occupy a corner position. A cannot be first because it must be immediately after C. F cannot be first because F is explicitly stated not to be first or last. Only B can occupy the first position without breaking any condition.

Common Pitfalls:
A common error is to misread “only E joined after C and D” and place E in a non last position, which then allows other friends to be after D, violating the condition. Another pitfall is forgetting that the block B, C, A must be consecutive and in that exact order. Some candidates also overlook that both D and F have restrictions on corner positions. Drawing a six slot diagram and filling it systematically helps prevent such mistakes.

Final Answer:
The first person to join the institute was B.