Number Prop

This topic has expert replies
Legendary Member
Posts: 869
Joined: Wed Aug 26, 2009 3:49 pm
Location: California
Thanked: 13 times
Followed by:3 members

Number Prop

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.
Source: — Data Sufficiency |

Master | Next Rank: 500 Posts
Posts: 399
Joined: Wed Apr 15, 2009 3:48 am
Location: india
Thanked: 39 times

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

Master | Next Rank: 500 Posts
Posts: 177
Joined: Thu Aug 14, 2008 11:59 am
Thanked: 25 times

by mp2437 » Wed Oct 07, 2009 10:56 am
^ agreed.

Legendary Member
Posts: 869
Joined: Wed Aug 26, 2009 3:49 pm
Location: California
Thanked: 13 times
Followed by:3 members

by heshamelaziry » Wed Oct 07, 2009 11:28 am
mp2437 wrote:^ agreed.
Could you provide an example please ?

Master | Next Rank: 500 Posts
Posts: 399
Joined: Wed Apr 15, 2009 3:48 am
Location: india
Thanked: 39 times

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