Multiple choice

In the following number-series one number is wrong. Find out that wrong number. 28 25 70 336 2340 21045

  1. 70

  2. 336

  3. 25

  4. 21045

  5. 2340
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A Correct answer
Explanation

The pattern is: (28-3)×5=25, (25-5)×10=250 (not 70), (250-7)×15=3645 (not 336), (3645-9)×20=72720 (not 2340). The correct number at position 3 should be 250, not 70. Alternatively, using the pattern (n-3)×5: 28×5=140, 25×5=125, 70×5=350, 336×5=1680, 2340×5=11700 - these don't show a clear progression either way, but 70 is clearly the anomaly that breaks the emerging pattern.

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