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VTMO 2014 — Grade 3 — semifinal Question 13

VTMO · VTMO 2014 — Grade 3 — semifinal

Question 13

Four people attend a party. On leaving, each person shakes hands once with every other person. How many handshakes occur?
  1. $3$
  2. $4$
  3. $6$
  4. $9$
  5. $12$