Live GMAT classes with Target Test Prep start Nov 1 and Nov 21. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 1
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 1 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand5 seats leftStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart 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.

Prompted by observations of seemingly related species

Expert replies
by himu » Tue Jan 08, 2013 9:10 pm
Prompted by observations of seemingly related species in neighboring locales that he made during his five-year voyage around the world on the HMS Beagle, Charles Darwin conceived his theory of natural selection in which all species evolved over time from a single ancestor or very few common ancestors.

A
in which all species evolved over time from a single ancestor or very few common ancestors

B
in which all species evolve from a single ancestor or very few common ancestors over time
C
whereby over time all species evolve from a single ancestor or very few common ancestors
D
whereby all species have evolved over time from a single ancestor or very few common ancestors
E
whereby all species evolved over time from a single ancestor or very few common ancestors
Join the discussion
Source: — Sentence Correction |

by pscher31 » Thu Jan 10, 2013 1:45 am
IMO A


It is the difference between two prepositions.

‘Whereby‘ means ‘by which’, hence you merely need to look at the words ‘by’ and ‘in’.

If you need to refer to the means of getting something done, you use ‘by’. You might say something like “the rules by which you must follow” or “the rules whereby you must follow”.

If you need to refer to an inclusion within a physical or abstract space, you use ‘in which‘. You might say something like “this is the chair in which I sit” or “this is the time in which this art belongs”.[/spoiler]
Join the discussion