Khan/khan-exercises — Issue #7194: Divisibility - divisibility
Author: KhanBugz
Created: 2011-11-28 17:45:45+00:00
State: open
Labels: chrome, win7, wrong-or-unclear

Reporter: jleddy@wcsks.com

All numbers divisible by 24 and 23 are also divisible by which of the following?
The prime factorization of 24 is 2×2×2×3.

The prime factorization of 23 is 23.

So, any number divisible by both must have 2×2×2×3×23 as part of its prime factorization.

Such a number is divisible by 12, since the prime factorization of 12 is 2×2×3.

Answer
12
198
102
31
279

Says the answer is 12. 23 does not go into 12.

[divisibility.html?seed=150&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/divisibility.html?seed=150&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/divisibility.html?seed=150&problem=0&debug&activity=%5B%5B%22hint-activity%22%2C%220%22%2C70%5D%2C%5B%22hint-activity%22%2C%220%22%2C74%5D%2C%5B%22hint-activity%22%2C%220%22%2C112%5D%2C%5B%22hint-activity%22%2C%220%22%2C120%5D%5D)

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