Khan/khan-exercises — Issue #6517: Counting 2 - Don't understand the hint
Author: KhanBugz
Created: 2011-11-17 09:07:07+00:00
State: open
Labels: chrome, hard, xp

Reporter: kakipatakie@gmail.com

The last part of the hint says to divide by 2 but I don't understand why you do that. 11*10 = 110 (there are 11 people shaking 10 people's hands). But to make sure we don't double-count, we divide by 2? Why 2? Why not 3 or 7 or 11?

[counting_2.html?seed=161&problem=handshakes](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/counting_2.html?seed=161&problem=handshakes&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/counting_2.html?seed=161&problem=handshakes&debug&activity=%5B%5B%22hint-activity%22%2C%220%22%2C276%5D%2C%5B%22hint-activity%22%2C%220%22%2C301%5D%2C%5B%22hint-activity%22%2C%220%22%2C322%5D%2C%5B%22hint-activity%22%2C%220%22%2C330%5D%5D)

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Mozilla/5.0 (Windows NT 5.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.120 Safari/535.2

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