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Manager
Joined: 16 Feb 2010
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Question Stats:
0% (00:00) correct
0% (00:00) wrong based on 0 sessions
How many odd three-digit integers greater than 800 are there such that all their digits are different?
(C) 2008 GMAT Club - m10#13
* 40 * 56 * 72 * 81 * 104
If the number begins with 8, there are 5*8 = 40 possibilities (5 possibilities 1,3,5,7,9for the last digit and 8 possibilities for the middle digitwhy 8? it should be 9 (0,1,2,3,4,5,6,7,9)).
If the number begins with 9, there are 4*8 = 32 possibilities (4 possibilities for the last digit and 8 possibilities for the middle digitsame as above...it should be 9...).
In all, there are 40 + 32 = 72 numbers that satisfy the constraints. The correct answer is C. |
thanks
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Manager
Joined: 25 Jun 2010
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You are missing that the last digit and middle digit can't be same. Posted from my mobile device
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Manager
Joined: 16 Feb 2010
Posts: 236
Followers: 2
Kudos [?]:
22
[0], given: 16
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anshumishra wrote: You are missing that the last digit and middle digit can't be same. Posted from my mobile device  gotta
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