Digits 2 & 5

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Digits 2 & 5

by pankajks2010 » Sat May 14, 2011 10:00 pm
How many different integers between 100 & 999 inclusive do not have any digit which is a 2 or 5?

a)408
b)446
c)448
d)512
e)700


[spoiler]OA: C[/spoiler]

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Not sure, if this question is already discussed on the forum or not.
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by manpsingh87 » Sat May 14, 2011 11:28 pm
pankajks2010 wrote:How many different integers between 100 & 999 inclusive do not have any digit which is a 2 or 5?

a)408
b)446
c)448
d)512
e)700


[spoiler]OA: C[/spoiler]

Courtesy: 800score.com
Not sure, if this question is already discussed on the forum or not.
digits available 0,1,2,3,4,5,6,7,8,9..!! digits that we don't want to appear in a number are 2 and 5.
-,-,- ; left most digit can be filled with any of the remaining 7 digits in 7 ways(1,3,4,6,7,8,9);
digit in the ten's place can be filled with (0,1,3,4,6,7,8,9)any of these 8 numbers in 8 ways, similarly digit at the unit's place can be filled with any of these (0,1,3,4,6,7,8,9) eight number in 8 ways,
hence total number of ways=7*8*8=448 hence C
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by pankajks2010 » Sun May 15, 2011 12:33 am
thanks a lot manpsingh..somehow, I struggle a lot with P&C questions. However, you have made it look very simple. Thanks again!!

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by manpsingh87 » Sun May 15, 2011 12:36 am
pankajks2010 wrote:thanks a lot manpsingh..somehow, I struggle a lot with P&C questions. However, you have made it look very simple. Thanks again!!
you're always.. welcome...!!! :D
O Excellence... my search for you is on... you can be far.. but not beyond my reach!