Multiple choice general knowledge math & puzzles

Seven men arrive at a meeting and each of them shakes hands once with each of others. How many hand shakes does that make?

  1. 42

  2. 28

  3. 56

  4. 21
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The handshake formula is n(n-1)/2 for n people. With 7 people: 7×6/2 = 21. Each of the 7 people shakes hands with 6 others, but this counts each handshake twice, so we divide by 2.

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