|
Author |
Message |
|
TAGS:
|
|
|
Manager
Joined: 31 Jul 2006
Posts: 243
Followers: 2
Kudos [?]:
12
[0], given: 0
|
If c and d are integers, is c even? a. c(d+1) is even b. [#permalink]
 11 Oct 2008, 01:28
Question Stats:
0% (00:00) correct
 0% (00:00) wrong based on 0 sessions
If c and d are integers, is c even?
a. c(d+1) is even
b. (c+2)(d+2) is even
|
|
|
|
|
|
|
Manager
Joined: 07 Jan 2008
Posts: 88
Followers: 2
Kudos [?]:
16
[0], given: 1
|
Re: Even numbers DS [#permalink]
11 Oct 2008, 05:44
Ans is E.
(a) when d is odd, c can be even or odd
(b) when (c+2) is even, c is even. when (d+2) is even, c can be odd or even.
both together doesn't give any info. So E.
|
|
|
|
|
|
SVP
Joined: 05 Jul 2006
Posts: 1564
Followers: 4
Kudos [?]:
65
[0], given: 37
|
Re: Even numbers DS [#permalink]
12 Oct 2008, 14:28
redbeanaddict wrote: If c and d are integers, is c even?
a. c(d+1) is even
b. (c+2)(d+2) is even from a even*odd(d is even) or odd *even thus(d is odd) or both even ( c even d is odd) from 2 odd *even ( c is odd, d is even) or even*odd ( c is even, d is odd) or even * even thus both are even both together E
|
|
|
|
|
|
Senior Manager
Joined: 21 Apr 2008
Posts: 275
Location: Motortown
Followers: 0
Kudos [?]:
65
[0], given: 0
|
Re: Even numbers DS [#permalink]
12 Oct 2008, 14:33
Clearly E
I will go with the explanations above
|
|
|
|
|
|
SVP
Joined: 17 Jun 2008
Posts: 1592
Followers: 7
Kudos [?]:
132
[0], given: 0
|
Re: Even numbers DS [#permalink]
12 Oct 2008, 23:11
C for me.
from 1: c can be even and d can be odd / even or
c and d will be odd.
From 2: c and d can be even, c can be even and d can be odd/even, c is odd and d is even.
Combining the two,
c is even and d can be odd/even. Hence, sufficient.
|
|
|
|
|
|
Intern
Joined: 02 Oct 2008
Posts: 17
Followers: 0
Kudos [?]:
0
[0], given: 0
|
Re: Even numbers DS [#permalink]
13 Oct 2008, 00:26
Redbeanaddict's answer made me rethink ... C. A) C ODD and D even -- not possible B) C ODD and D EVEN -- not possible So combining the two, C has to be even and D can be odd/even. Amazing what time pressure does to our thinking. 
|
|
|
|
|
|
Senior Manager
Joined: 21 Apr 2008
Posts: 275
Location: Motortown
Followers: 0
Kudos [?]:
65
[0], given: 0
|
Re: Even numbers DS [#permalink]
13 Oct 2008, 04:59
Answer is C  I think I was  Unlike guttal07, may be I need to be under time pressure to solve the problem properly 
|
|
|
|
|
|
Current Student
Joined: 28 Dec 2004
Posts: 3437
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 11
Kudos [?]:
135
[0], given: 2
|
Re: Even numbers DS [#permalink]
13 Oct 2008, 16:14
If c and d are integers, is c even?
a. c(d+1) is even
b. (c+2)(d+2) is ev
1) cd+c=even, well we dont anything here c could be even.. or odd,
2) again same thing cd+2c+2d+4=even
together
cd+c=even, ok..even+c+2d=even
we know that 2d is even, even+c=even, which means C has to be even
C it is
|
|
|
|
|
|
|
Re: Even numbers DS
[#permalink]
13 Oct 2008, 16:14
|
|
|
|
|
|
|
|
|
Similar topics |
Author |
Replies |
Last post |
|
Similar
Topics:
|
 |
|
|
If c and d are integers, is c even? 1) c(d+1) is even 2)
|
arjsingh1976 |
2 |
03 Dec 2006, 05:40 |
|
|
|
|
If c and d are integers, is c even? (1) c(d + 1) is even.
|
nick_sun |
7 |
16 Apr 2007, 00:34 |
|
|
|
|
If c and d are integers, is c even? 1) c(d+1) is even. 2)
|
lanter1 |
4 |
29 Jul 2007, 13:04 |
|
|
|
|
If c and d are integers, is c even? 1) c(d+1) is even 2)
|
bsjames2 |
2 |
18 Feb 2008, 09:14 |
|
|
1
|
|
If c and d are integers, is c even? (1) c(d+1) is even (2)
|
tarek99 |
7 |
25 Jul 2008, 02:50 |
|
|
|
|
|
|
close
