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Number Prop

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by heshamelaziry » Wed Oct 07, 2009 8:09 am
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.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
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Source: — Data Sufficiency |

by xcusemeplz2009 » Wed Oct 07, 2009 8:54 am
IMO A

1) suff ; adding 9 to k will inc its 10th digit by 1; therefore its 2
2) not suff it can be 1 or 2
It does not matter how many times you get knocked down , but how many times you get up
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by mp2437 » Wed Oct 07, 2009 10:56 am
^ agreed.
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by heshamelaziry » Wed Oct 07, 2009 11:28 am
mp2437 wrote:^ agreed.
Could you provide an example please ?
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by xcusemeplz2009 » Wed Oct 07, 2009 11:39 am
heshamelaziry wrote:
mp2437 wrote:^ agreed.
Could you provide an example please ?
statement 1) k can be xyz( z=1....9) ; if you add 9 irrespective of its value as in this case i.e z+9 will give you a value of 10 i.e 10th dig so k+9 will become a number of x(y+1)z ; whereas y+1=3 therefore y=2

hence 10th dig is 2

Statment 2) xyz when u add 4 to z carryover depends on value of z;i.e if z>5 then there is a carry over aand if z<5 then there will be no carry over ; so we get two values
hence not suff.
It does not matter how many times you get knocked down , but how many times you get up
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