number properties

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number properties

by roger federer » Thu Mar 11, 2010 2:33 pm
If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?
(1) The tens digit of k + 9 is 3.
(2) The tens digit of k + 4 is 2.
Source: — Data Sufficiency |

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by dchilmak » Thu Mar 11, 2010 5:26 pm
Answer is (D) .

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by papgust » Thu Mar 11, 2010 6:00 pm
Moved to data sufficiency!

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by ganeshraj » Thu Mar 11, 2010 8:39 pm
IMO =A

For (2), The value of the Tens digit depends on the units digit of K.

The Tens digit of K can be
1 when units digit is >= 6 or
2 when units digit is <6.

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by kstv » Thu Mar 11, 2010 9:10 pm
If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?
(1) The tens digit of k + 9 is 3. Possible unit digit any no from 1 to 9. Adding 9 to it will make the total any value from
10 to 18. So the Tens digit should be 2 so that k+9 will have the tens digit as 3. Sufficient.

(2) The tens digit of k + 4 is 2. No conclusion can be drawn on similar lines. k = 124, 118 are all valid . Insufficient

IMO A