Wrong Term in the Fibonacci-Sum Style Series: 1, 3, 4, 7, 11, 18, 27, 47 — exactly one term is incorrect. Identify it and explain the intended rule (sum of previous two).

Introduction / Context:
A common construction in series questions is a(n) = a(n-1) + a(n-2). We check each position to find the unique violation.

Given Data / Assumptions:

• Given sequence: 1, 3, 4, 7, 11, 18, 27, 47.
• We expect each term from the 3rd onward to equal the sum of the two previous terms.

Concept / Approach:
Systematically verify the sum-of-previous-two property; the first mismatch highlights the wrong term.

Step-by-Step Solution:
4 = 1 + 3 ✓7 = 3 + 4 ✓11 = 4 + 7 ✓18 = 7 + 11 ✓Next should be 11 + 18 = 29, but the series shows 27 → mismatch.With 29 in place of 27, the next term is 18 + 29 = 47, which matches the last term.

Verification / Alternative check:
Only by changing 27 to 29 does the entire series align to the rule without further edits.

Why Other Options Are Wrong:

• 18, 11, 7, 47: each satisfies the rule relative to its neighbors when 27 is corrected to 29.

Common Pitfalls:
Changing two terms to “force-fit” a different rule. The minimal edit principle points to 27 as the lone error.

Final Answer:
27