Eight people attend a dinner party. Every attendee shakes hands with every other person at the table exactly once, with the exception of two stubborn rivals who refuse to shake each other's hand. How many total handshakes occur?
27
With 8 individuals, the complete number of pairings is (8 * 7) / 2 = 28 handshakes. Subtracting the single excluded handshake between the two rivals leaves 27 handshakes.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Easy. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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