Which number replaces the question mark in the series? 5, 13, 25, ?, 61
2023
Which number replaces the question mark in the series?
5, 13, 25, ?, 61
Answer: A. 41 — ConceptIn a difference-based number series, subtract consecutive terms and look for a regular pattern in the differences. If the differences form an…
- A.
41
- B.
42
- C.
31
- D.
43
Attempted by 38 students.
Show answer & explanation
Correct answer: A
Concept
In a difference-based number series, subtract consecutive terms and look for a regular pattern in the differences. If the differences form an arithmetic progression, extend that progression before restoring the missing term.
Application
13 − 5 = 8 and 25 − 13 = 12; the difference increases by 4.
The next difference is 12 + 4 = 16, so the missing term is 25 + 16 = 41.
The following difference is 16 + 4 = 20, and 41 + 20 = 61.
Cross-check
The complete sequence of differences is 8, 12, 16, 20, which increases uniformly by 4. Therefore, the missing number is 41.