Last visit was: 20 Dec 2024, 18:22 It is currently 20 Dec 2024, 18:22

Close

GRE Prep Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Verbal Expert
Joined: 18 Apr 2015
Posts: 30425
Own Kudos [?]: 36778 [3]
Given Kudos: 26094
Send PM
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12231 [0]
Given Kudos: 136
Send PM
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12231 [2]
Given Kudos: 136
Send PM
Intern
Intern
Joined: 19 Oct 2020
Posts: 33
Own Kudos [?]: 42 [1]
Given Kudos: 41
Send PM
Re: If the sum of two integers is 6, then it must be true that [#permalink]
1
GreenlightTestPrep wrote:
Carcass wrote:
If the sum of two integers is 6, then it must be true that

(A) both integers are even
(B) both integers are odd
(C) both integers are positive
(D) if one integer is negative, the other is positive
(E) if one integer is positive, the other is negative


Kudos for the right answer and explanation

Another approach.

We're asked to find a statement that MUST be true. So, if we can find a case where a statement is false, we can ELIMINATE that answer choice.

(A) both integers are even : it could be the case that the numbers are 1 and 5. ELIMINATE A
(B) both integers are odd : it could be the case that the numbers are 2 and 4. ELIMINATE B
(C) both integers are positive : it could be the case that the numbers are -1 and 7. ELIMINATE C
(D) if one integer is negative, the other is positive : Can't think of a counterexample so KEEP D for now
(E) if one integer is positive, the other is negative : it could be the case that the numbers are 1 and 5. ELIMINATE E

By the process of elimination, the correct answer is D

Cheers,
Brent



what is the difference between option D and E ?
I don't see any difference between them .
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12231 [1]
Given Kudos: 136
Send PM
If the sum of two integers is 6, then it must be true that [#permalink]
1
mrk9414 wrote:
what is the difference between option D and E ?
I don't see any difference between them .


Many people will view D and E as identical, but they're aren't.
The (incorrect) idea is that the conditional statement "If A is true then B must also be true" implies a second conditional statement that says "If B is true then A must also be true"
Here's a counter-example to show why this is not true:

"If an animal is a cow, then that animal must have 2 eyes"
I think we all agree on the truth of this conditional.
However, does this also mean the following conditional must also be true: "If an animal has 2 eyes, then that animal must be a cow"?
No.
Intern
Intern
Joined: 21 Jan 2021
Posts: 23
Own Kudos [?]: 6 [0]
Given Kudos: 0
Send PM
Re: If the sum of two integers is 6, then it must be true that [#permalink]
D and E mean different things bc of the different conditionals. Be careful:
Prep Club for GRE Bot
Re: If the sum of two integers is 6, then it must be true that [#permalink]
Moderators:
GRE Instructor
88 posts
GRE Forum Moderator
37 posts
Moderator
1115 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne