Data sufficiency- Integers.

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Tue Aug 10, 2010 8:26 am
Thanked: 1 times

Data sufficiency- Integers.

by harpritsn » Thu Aug 26, 2010 8:17 am
hi,

If m is an integer, is m odd?

1. m/2 is not an even integer.

2. m-3 is an even integer.

its from OG12- Data sufficiency. the answer is "B".

My doubt is. why not both, it means even "A" is sufficient to give the answer.[/i]
Source: — Data Sufficiency |

User avatar
Legendary Member
Posts: 659
Joined: Mon Dec 14, 2009 8:12 am
Thanked: 32 times
Followed by:3 members

by Gurpinder » Thu Aug 26, 2010 8:40 am
If m is an integer, is m odd?


1. m/2 is not an even integer.

anything divisible by 2 IS an EVEN integer. so if m was divisible by 2 it MUST be even. However, we are told that m/2 is not an EVEN integer. Don't automatically think that its odd.

Then that means that M could be a fraction. lets say that its m=1. then m/2=1/2 < --- thats not even. so m = 1

now lets say m=2, so 2/2=1 <-- thats not even either.

m=1 or 2

thats why this one is insufficient.

the trick here is in the wording of the question. if a number is not even, dont automatically think that its odd. it could not even be an integer. it could be a fraction.


2. m-3 is an even integer.

this one is sufficient.

odd-odd=even

therefore, m=odd.
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.