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by chaitanya.mehrotra » Sun Jul 24, 2011 11:45 am
If a and b are the digits of the two-digit number X, what is the remainder when X is divided by 9?

(1) a + b = 11

(2) X + 7 is divisible by 9

OA after some discussion , let me know also the amount of time it took to solve the question .It took me 3:56 min ;( to crack it .
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Source: — Data Sufficiency |

by gmat25 » Sun Jul 24, 2011 12:02 pm
chaitanya.mehrotra wrote:If a and b are the digits of the two-digit number X, what is the remainder when X is divided by 9?

(1) a + b = 11

(2) X + 7 is divisible by 9

OA after some discussion , let me know also the amount of time it took to solve the question .It took me 3:56 min ;( to crack it .
IMO D (80 sec)

Only Op A took some time as i checked all the possible combinations and against my expectation i find Op A SUFFICIENT

Op B is obviously SUFFICIENT

What's the OA???
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by Anurag@Gurome » Mon Jul 25, 2011 1:11 am
chaitanya.mehrotra wrote:If a and b are the digits of the two-digit number X, what is the remainder when X is divided by 9?

(1) a + b = 11

(2) X + 7 is divisible by 9
Statement 1: We know that if sum of the digits of an integer is divisible by 9, then the integer will be divisible by 9. Now as the sum of the digits of X is 11, (x - 2) will be divisible by 9. Hence, when X is divided by 9 the remainder will be 2.

Sufficient

Statement 2 As (X + 7) is divisible by 9, (X - 2) will be divisible by 9 too. Hence, when X is divided by 9 the remainder will be 2.

Sufficient

The correct answer is D.
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by Ozlemg » Mon Jul 25, 2011 1:28 am
It is D

1.30 min.
The more you suffer before the test, the less you will do so in the test! :)
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by breakkgmat » Tue Jul 26, 2011 2:36 pm
D it is..2.05
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by winniethepooh » Tue Jul 26, 2011 3:02 pm
D.
Less than a minute.
1.Just remember, if the sum of the digits is divisible by 9 then the numb er is divisible by 9 too.
As the sum is 9+2 the remainder in each case is 2.
Hence, Sufficient.
2.If the remainder is added with 2 the number is divisible by 9. Hence, the remainder has to be 2.
to write this 1.5 minutes!
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