• The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh

Qs Pack: Two centuries ago, Tufe Peninsula became separated

This topic has 2 expert replies and 1 member reply

Top Member

Qs Pack: Two centuries ago, Tufe Peninsula became separated

Post Wed May 03, 2017 6:04 am
Two centuries ago, Tufe Peninsula became separated form the mainland, isolating on the newly formed Tufe Island a population of Turfil sunflowers. This population’s descendants grow to be, on average, 40 centimeters shorter than Turfil sunflowers found on the mainland. Tufe Island is significantly drier than Tufe Peninsula was. So the current average height of Tufe’s Turfil sunflowers is undoubtedly at least partially attributable to changes in Tufe’s environmental conditions.

Which of the following is an assumption on which the argument depends?

A. There are no types of vegetation on Tufe Island that are known to benefit from dry conditions.

B. There were about as many Turfil sunflowers on Tufe Peninsula two centuries ago as there are on Tufe Island today.

C. The mainland’s environment has not changed in ways that have resulted in Turfil sunflowers on the mainland growing to be 40 centimeters taller than they did two centuries ago.

D. The soil on Tufe Island, unlike that on the mainland, lacks important nutrients that help Turfil sunflowers survive and grow tall in a dry environment.

E. The 40-centimeter height difference between the Turfil sunflowers on Tufe Island and those on the mainland is the only difference between the two populations.


OA: C

Hi Verbal Experts,
Could you please clarify why Option D is wrong ?

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Wed May 03, 2017 10:42 am
When we're looking for an ASSUMPTION on which the argument DEPENDS, we want to ask ourselves, "does this thing HAVE to be true for the conclusion to hold?"

Many students mix up STRENGTHEN and ASSUMPTION questions. For strengthen, we simply ask "does this help the conclusion? Does it make the conclusion more likely to be true?" But it's not necessarily something that has to be true.

Here's the structure of this argument:

Premises:
- Tufe Peninsula became separated form the mainland, isolating on the newly formed Tufe Island a population of Turfil sunflowers
- Tufe Island sunflowers are 40 centimeters shorter than Turfil sunflowers found on the mainland
- Tufe Island is significantly drier than Tufe Peninsula was

Conclusion:
The current average height of Tufe’s Turfil sunflowers is undoubtedly at least partially attributable to changes in Tufe’s environmental conditions.

Sometimes the best way to find out what the argument is missing is to ask, "is there any way for the conclusion NOT to be true, while keeping the premises true?"

We know that the island and the mainland have different environments now, and that the island has shorter sunflowers. We even know that the island is drier than the peninsula used to be. But could there be some way for the height difference in sunflowers NOT to be caused by the island's changes? What about the mainland's changes? We don't know about the height of sunflowers 200 years age. We're assuming the island flowers shrank, but maybe the mainland ones grew!

A. There are no types of vegetation on Tufe Island that are known to benefit from dry conditions.
Other types of vegetation are irrelevant to our conclusion about sunflowers.

B. There were about as many Turfil sunflowers on Tufe Peninsula two centuries ago as there are on Tufe Island today.
NUMBER of sunflowers = irrelevant to conclusion about HEIGHT of sunflowers.

C. The mainland’s environment has not changed in ways that have resulted in Turfil sunflowers on the mainland growing to be 40 centimeters taller than they did two centuries ago.
Bingo! Try negating this one - if the mainland's environment DID change, then our conclusion falls apart.

D. The soil on Tufe Island, unlike that on the mainland, lacks important nutrients that help Turfil sunflowers survive and grow tall in a dry environment.
This one strengthens - it gives more reason to believe that changes on the island affected the sunflower height. But does it HAVE to be true? Nope! Other changes besides the soil could still account for it. If we negate it, it doesn't destroy the argument.

E. The 40-centimeter height difference between the Turfil sunflowers on Tufe Island and those on the mainland is the only difference between the two populations.

Irrelevant. The height difference is the only difference that our conclusion deals with, but it wouldn't have to be the only difference between the two species.

Hope that helps!

_________________


Ceilidh Erickson
Manhattan Prep GMAT & GRE instructor
EdM in Mind, Brain, and Education
Harvard Graduate School of Education


Manhattan Prep instructors all have 99th+ percentile scores and expert teaching experience.
Sign up for a FREE TRIAL, and learn why we have the highest ratings in the GMAT industry!

  • +1 Upvote Post
  • Quote
  • Flag
Free Manhattan Prep online events - The first class of every online Manhattan Prep course is free. Classes start every week.

GMAT/MBA Expert

Free Manhattan Prep online events - The first class of every online Manhattan Prep course is free. Classes start every week.

Top Member

NandishSS Master | Next Rank: 500 Posts Default Avatar
Joined
05 Jun 2015
Posted:
344 messages
Followed by:
2 members
Upvotes:
3
Most Conversational Member
Post Sun Nov 26, 2017 8:27 pm
HI Ceilidh, /Mitch,

In this CR question, Can assumption be only mainland’s environment has not changed?

In general

Can assumption be to avoid other alternate reason?

Thanks
Nandish

  • +1 Upvote Post
  • Quote
  • Flag

Top First Responders*

1 GMATGuruNY 67 first replies
2 Rich.C@EMPOWERgma... 44 first replies
3 Brent@GMATPrepNow 40 first replies
4 Jay@ManhattanReview 25 first replies
5 Terry@ThePrinceto... 10 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 image description GMATGuruNY

The Princeton Review Teacher

132 posts
2 image description Rich.C@EMPOWERgma...

EMPOWERgmat

112 posts
3 image description Jeff@TargetTestPrep

Target Test Prep

95 posts
4 image description Scott@TargetTestPrep

Target Test Prep

92 posts
5 image description Max@Math Revolution

Math Revolution

91 posts
See More Top Beat The GMAT Experts