Multiple choice

Find the term which does not fit into the series. 121, 143, 165, 186, 209

  1. 121

  2. 165

  3. 209

  4. 186
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Check if each number is divisible by 11: 121÷11=11, 143÷11=13, 165÷11=15, 209÷11=19. All divide evenly. However, 186÷11=16.91, which is not an integer. The pattern is '11 multiplied by consecutive odd numbers (11, 13, 15, 19)', and 186 breaks this pattern.

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