Multiple choice

In the following number series, a term is wrong. Find the wrong term in the following number series. 21, 42, 225, 3024, 60480, 1814400

  1. 1814400

  2. 60480

  3. 3024

  4. 42

  5. 225
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E Correct answer
Explanation

The series is 21, 42, 225, 3024, 60480, 1814400. Pattern: 21 × 2 = 42, 42 × 5 + 15 = 225, 225 × 13 + 99 = 3024, 3024 × 20 + 0 = 60480, 60480 × 30 = 1814400. The correct pattern is n × position + (previous increment - 24): 21 × 2 = 42 (should be 21 × 2 + 0 = 42), 42 × 3 + 12 = 138 (but we have 225), 138 × 4 + 24 = 576 (but we have 3024). The term 225 breaks the pattern.

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