Multiple choice

Find the wrong term in the following number series: 15, 21, 24, 30, 33, 39, 52, 57

  1. 30

  2. 33

  3. 39

  4. 52

  5. 57
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The pattern is +6, +3, +6, +3, +6, +3. 15+6=21, 21+3=24, 24+6=30, 30+3=33, 33+6=39, 39+3=42. The term 52 is incorrect; it should be 42.

AI explanation

This sequence is created by alternately adding 6 and 3 to the previous numbers. We add 6 to 15 to get 21, add 3 to 21 to get 24, add 6 to 24 to get 30, add 3 to 30 to get 33, add 6 to 33 to get 39, and add 3 to 39 to get 42. Since the series shows 52 instead of 42, that number is incorrect. The result is 52.

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