Machine-translated by Google. Questions are authored in English.
Top

Discussion

There are 30 people in a party. If everyone is to shake hands with one another, how many hand shakes are possible?

  • A.180
  • B.256
  • C.386
  • D.435

Answer: D

A handshake involves two people and the order does not matter, so the count is a combination.

\[ {}^{30}C_{2} = \frac{30 \times 29}{2} = 435 \]

Each of the 30 people shakes 29 hands, but that counts every handshake twice, hence the division by 2.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.