Multiple choice

Find the missing term of the following series. 15 14 18 9 25 ?

  1. 36

  2. 125

  3. 0

  4. 82
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C Correct answer
Explanation

The series follows an alternating pattern with square numbers: subtract 1², add 2², subtract 3², add 4², subtract 5². Starting from 15: 15-1=14, 14+4=18, 18-9=9, 9+16=25, 25-25=0. The operations alternate between subtraction and addition while the squared numbers increase consecutively (1, 4, 9, 16, 25). Option A (36) incorrectly assumes only addition, while Option D (82) doesn't follow the pattern.

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