What should come in place of the question mark (?) in the given series? 15,…
2026
What should come in place of the question mark (?) in the given series?
15, 21, 27, 33, 39, ?
Answer: A. 45 — ConceptIn an arithmetic progression, the difference between consecutive terms remains constant. The next term is found by adding this common difference to the…
- A.
45
- B.
42
- C.
44
- D.
43
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Show answer & explanation
Correct answer: A
Concept
In an arithmetic progression, the difference between consecutive terms remains constant. The next term is found by adding this common difference to the last known term.
Application
Compute consecutive differences: 21 − 15 = 6, 27 − 21 = 6, 33 − 27 = 6, and 39 − 33 = 6.
Since the common difference is 6, add 6 to the last shown term: 39 + 6 = 45.
Cross-check
Extending backward from 45 by the same difference gives 45 − 6 = 39, which matches the preceding term. Therefore, the missing number is 45.