Multiple choice

Which one number is wrong in the given series? 9, 20, 35, 55, 80, 114

  1. 20

  2. 35

  3. 80

  4. 114
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Analyzing the series 9, 20, 35, 55, 80, 114. Differences: 11, 15, 20, 25, 34. Second differences: 4, 5, 5, 9 - not consistent. Let's check pattern: 9, 9+11=20, 20+15=35, 35+20=55, 55+25=80. The additions increase by 4, 5, 5... Should be 4,5,6,7 pattern giving: 9+11=20, 20+15=35, 35+20=55, 55+26=81, 81+33=114. So 80 should be 81. Option C (80) is the wrong number.

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