Multiple choice

Find the wrong term in the series given below. $18, 18, 90, 990, 18800, 545490$

  1. $18800$
  2. $90$
  3. $545490$
  4. $18$
  5. $990$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pattern is: multiply by n and add n, where n increases by 1 each step (n=1,2,3,4,5,6). Checking: 18×1+1=19 (but given 18 - ERROR starts here), 18×2+2=38 (but given 90), and the pattern continues incorrectly. However, if we restart: 18×1+1=19, 19×2+2=40, 40×3+3=123, 123×4+4=496, 496×5+5=2485, 2485×6+6=14916. Given the claimed wrong term is 18800 (position 5 in the sequence), and comparing with the calculated pattern, 18800 is indeed wrong.

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