Last visit was: 19 Nov 2025, 16:25 It is currently 19 Nov 2025, 16:25
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
GMAT 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 GMAT 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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
655-705 Level|   Strengthen|         
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,390
Own Kudos:
778,368
 [11]
Given Kudos: 99,977
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,390
Kudos: 778,368
 [11]
As far as we know, Earth is the only planet on which life has evolved, 27 Sep 2019, 03:14
Kudos
Add Kudos
11
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

65% (hard)

Question Stats:

63% (02:20) correct 37% (02:23) wrong based on 568 sessions

History

Date
Time
Result
Not Attempted Yet
As far as we know, Earth is the only planet on which life has evolved, and all known life forms are carbon-based. Therefore, although there might exist noncarbon-based life on planets very unlike Earth, our scientific estimates of the probability of extraterrestrial life should be generated from estimates of the number of planets like Earth and the likelihood of carbon-based life on those planets.

Which one of the following general principles most strongly supports the recommendation?


(A) There is no good reason to think that unobserved phenomena closely resemble those that have been observed.

(B) A scientific theory that explains a broad range of phenomena is preferable to a competing theory that explains only some of those phenomena.

(C) It is preferable for scientists to restrict their studies to phenomena that are observable and forego making estimates about unobservable things.

(D) A scientific theory that explains observed phenomena on the basis of a few principles that are independent of each other is preferable to a theory that explains those same phenomena on the basis of many independent principles.

(E) Estimations of probability that are more closely tied to what is known are preferable to those that are less closely tied to what is known.
ShowHide Answer
Official Answer
E
User avatar
daagh
User avatar
Major Poster
Joined: 19 Feb 2007
Last visit: 16 Oct 2020
Posts: 5,264
Own Kudos:
42,419
 [1]
Given Kudos: 422
Status: enjoying
Location: India
WE:Education (Education)
Expert
Expert reply
Posts: 5,264
Kudos: 42,419
 [1]
As far as we know, Earth is the only planet on which life has evolved, 30 Sep 2019, 05:57
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The only reason I select E is for the reason that the prompt and the E talk of estimations of the probabality rather than as all other chocies talk of different other things. things
User avatar
deborit
User avatar
Joined: 08 Jul 2023
Last visit: 18 May 2025
Posts: 23
Own Kudos:
5
Given Kudos: 511
Posts: 23
Kudos: 5
As far as we know, Earth is the only planet on which life has evolved, 02 Jun 2024, 21:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Why option A is wrong? I could understand A and E both are the options hard to eliminate but couldn't understand how the A option is eliminated

Posted from my mobile device
User avatar
azulonx
User avatar
Joined: 24 Jan 2024
Last visit: 05 Nov 2024
Posts: 7
Given Kudos: 70
Posts: 7
Kudos: 0
As far as we know, Earth is the only planet on which life has evolved, 03 Jun 2024, 10:48
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Question is: Which one of the following general principles most strongly supports the recommendation?

Recommendation is: "our scientists probability of extraterrestrial life should be generated from estimates of the number of planets like Earth and the likelihood of carbon-based life on those planets"
AKA: Scientist's probability of (E) should be generated from A and B, known estimations.

Why? "As far as we know, Earth is the only planet on which life has evolved, and all known life forms are carbon-based."
AKA: A and B quantities are known to exist with 100% certainty. C and D might exist, but we don't know for sure so it's 0% certainty.

The option the supports the most the recommendation will more closely support the WHY.

(A) There is no good reason to think that unobserved phenomena closely resemble those that have been observed.

C D which we cant observed aren't similar to A and B, which we can observe, therefore probability of E should be done with A and B.
This is wrong because it doesn't matter if C an D are similar to A and B; they're not including in P(E) because we don't know if C and D exist.

(B) A scientific theory that explains a broad range of phenomena is preferable to a competing theory that explains only some of those phenomena.

Irrelevant. Author is not proposing adherence to scientific theory to support his claim. We might assume that because he recommends to scientist that this will support this claim, but that is a trap.

(C) It is preferable for scientists to restrict their studies to phenomena that are observable and forego making estimates about unobservable things.
Scientist's probability of (E) should be generated from A and B, known estimations,....because it is better that scientist restrict their studies to phenomenas that are observable.... 
This is the tricky one because it has the word restric and scientist, which one could inferred are related to passage. However, this option doesn't given a direct reason to follow the recomendation. Instead it's appealing at what studies should limit themselves to. Also, like Option A, it talks about observable/unobservable things, which doesn't have the same level of certainty as "known" and therefore doesn't offer a strong reason why P(E) should come from known things.  


(D) A scientific theory that explains observed phenomena on the basis of a few principles that are independent of each other is preferable to a theory that explains those same phenomena on the basis of many independent principles.

Irrelevant. Author is not proposing adherence to scientific theory to support his claim. We might assume that because he recommends to scientist that this will support this claim, but that is a trap.


(E) Estimations of probability that are more closely tied to what is known are preferable to those that are less closely tied to what is known.

Scientist's probability of (E) should be generated from A and B, known estimations, because...... Scientist's probability of (E) generated from A and B are preferable to the ones that arent. 
This is the principle that directly supports the recommendation, and even says that the farther away the estimation is from "what-is-known" (100% certainty), the less preferable the estimation is. 
 
Moderators:
GMATNinja
GMAT Club Verbal Expert
7443 posts
GMATNinjaTwo
GMAT Club Verbal Expert
231 posts
miag
189 posts