String truncation from both ends – choose the next fragment Sequence: PERPENDICULAR, ERPENDICULA, RPENDICUL, ?

Introduction / Context:
This pattern removes one letter from the left and one from the right at each step. You must apply the same two-sided truncation to find the next fragment. Such problems test careful observation of string operations rather than numerical arithmetic.

Given Data / Assumptions:

• Starting word: PERPENDICULAR.
• Sequence so far: PERPENDICULAR → ERPENDICULA → RPENDICUL → ?
• Each arrow indicates one operation that deletes the first and the last character.

Concept / Approach:
Verify the rule on each transition. From the original to the second term, the first letter P and last letter R are dropped. From the second to the third, the first letter E and last letter A are dropped. Apply the same operation once more to obtain the fourth term.

Step-by-Step Solution:

Verification / Alternative check:
Counting lengths: 13 → 11 → 9 → 7, consistent with removing two letters each step. Visual inspection confirms the internal order of letters remains unchanged while trimming edges.

Why Other Options Are Wrong:

• PENDICUL: keeps the trailing L, but one letter must be removed from the right; it also fails the required length.
• PENDIC or ENDIC or ENDICU: either remove too many letters or drop from only one side, not both.
• Since none matches PENDICU exactly, the correct choice is “None of these”.

Common Pitfalls:
Forgetting that both ends are trimmed each time; assuming a single-end deletion; overlooking the expected length reduction of two characters per step.

Final Answer:
None of these