The missing term in the series 2, 7, 24, 77, ?, 723 is
2013
The missing term in the series 2, 7, 24, 77, ?, 723 is
Answer: A. 238 — ConceptA number series may be generated by applying the same operation while a secondary quantity follows its own pattern. Identify both parts of the rule and…
- A.
238
- B.
432
- C.
542
- D.
320
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Correct answer: A
Concept
A number series may be generated by applying the same operation while a secondary quantity follows its own pattern. Identify both parts of the rule and verify that one rule explains every transition.
Application
Multiply 2 by 3 and add 1: 2 × 3 + 1 = 7.
Multiply 7 by 3 and add the next odd number, 3: 7 × 3 + 3 = 24.
Multiply 24 by 3 and add 5: 24 × 3 + 5 = 77.
Multiply 77 by 3 and add 7: 77 × 3 + 7 = 238.
Cross-check
Continue the same rule with the next odd number, 9: 238 × 3 + 9 = 723, which matches the final term given in the series.
Therefore, the missing term is 238.