BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

editor

Expert replies
by gmatmachoman » Sun Dec 06, 2009 4:11 am
To the editor:

In 1960, an astronomer proposed a mathematical model for determining whether extraterrestrial life exists. It was based on the assumptions that life as we know it could exist only on a planet and that many stars are, like our Sun, orbited by planets, On the basis that there are nine planets in our solar system and one of them has life as we know it, the astronomer predicted that there are as many as one million extraterrestrial civilizations across all solar systems. Yet astronomers to date have not detected even one planet outside our solar system. This indicates that the astronomer's model is wrong, and life as we know it exists only on the plant Earth.

Clay Moltz

Which one of the following, if accepted by Clay Moltz would require him to reconsider his conclusion?

(A) Forms of life other than life as we know it exist on other planets.
(B) There are many stars that are not orbited by planets.
(C) Detecting planets outside our solar system requires more sophisticated instruments than are currently available.
(D) The soundness of the conclusion reached by applying a mathematical model depends on the soundness of the assumptions on which the model is based.
(E) Due to sheer distances and expanses of space involved, any extraterrestrial civilization would have great difficulty communicating with ours.

IMO D
Join the discussion
Source: — Critical Reasoning |

by godspeed » Sun Dec 06, 2009 4:52 am
IMO its C
Join the discussion

by nakul_anand » Sun Dec 06, 2009 5:23 am
IMO C
Join the discussion

by gmatv09 » Sun Dec 06, 2009 8:52 am
Agree with others .... C
Join the discussion

by Testluv » Sun Dec 06, 2009 7:02 pm
Yep, the answer is definitely choice C here.

What is his main reason for concluding that life exists only on Earth? It is the second-to-last sentence:

"Yet astronomers to date have not detected even one planet outside our solar system."

But choice C tells us that the reason we have to date failed to detect other planets might not be because there aren't any other planets; rather it might be because our equipment sucks. Then, Mr. Moltz would have to reconsider arriving at his hasty conclusion so fast!
Kaplan Teacher in Toronto
Join the discussion

by okigbo » Sun Dec 06, 2009 8:54 pm
testluv,

can u pls explain why d is wrong? thanks
Join the discussion

by Testluv » Sun Dec 06, 2009 9:36 pm
I think the reason choice D is tempting is that it sounds sensible and also because it is within the scope of the argument (mathematical model). Yes, choice D sounds very sensible. But Mr. Moltz likely already accepts that the soundness of a mathematical model's conclusion depends on the soundness of the assumptions on which the model is based; nothing in his argument denies this.

The math model itself is not based on any questionable assumptions. Instead, Mr. Moltz' attempted refutation of the math model assumes that the equipment is sensitive enough to detect planets outside of the solar system.
Kaplan Teacher in Toronto
Join the discussion

by joseph32 » Sun May 15, 2016 10:35 pm
In my opinion C is the most logical one.
Join the discussion