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SEAMO 2027 - Paper A - SET 02 - Self-study Question 9

SEAMO · SEAMO 2027 - Paper A - SET 02 - Self-study

Question 9

Find the value of \(1-2+3-4+5-6+\cdots-20+21\).
  1. 11
  2. 13
  3. 15
  4. 17
  5. 21