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SEAMO 2027 - Paper A - SET 11 - Self-study Question 15

SEAMO · SEAMO 2027 - Paper A - SET 11 - Self-study

Question 15

Find the value of 1−2+3−4+5−6+⋯+19−20+21.
  1. 8
  2. 9
  3. 10
  4. 11
  5. 12