Multiple choice general knowledge math & puzzles

At the end of a banquet 10 people shake hands with each other. How many handshakes will there be in total?

  1. 90

  2. 45

  3. 100

  4. 50
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

With 10 people, each person shakes hands with 9 others. This gives 10 × 9 = 90 handshakes counted. But each handshake involves 2 people, so we've counted each handshake twice. Total handshakes = (10 × 9)/2 = 45. Formula: nC2 = n(n-1)/2 for n people.

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