Multiple choice

In the following number series one number is wrong. Find that wrong number. 4.5 6.5 16 54 213 1071

  1. 16

  2. 54

  3. 6.5

  4. 213

  5. 1071
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern is: multiply by 1 and add 2, then multiply by 2 and add 3, then multiply by 3 and add 4, then multiply by 4 and add 5, then multiply by 5 and add 6. Starting from 4.5: 4.5×1+2=6.5, 6.5×2+3=16, 16×3+4=52 (not 54), 52×4+5=213, 213×5+6=1071. Therefore 54 is the wrong number.

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