Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. 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 22
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 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
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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

OG Work DS Problem

Expert replies
by okigbo » Mon Oct 19, 2009 9:48 am
I thought I was decent at work problems but can't figure this out. Please help.

Machine X & Y produce identical bottles at different constant rates. Machine X, operating alone for 4 hours filled part of a production lot; then Machine Y operating alone for 3 hours filled the rest of the lot. How many hours would it take Machine X operating alone to fill the entire lot?

1. Machine X produces 30 bottles / min
2. Machine X produced twice as many bottles in 4 hours as Machine Y produced in 3 hours
Join the discussion
Source: — Data Sufficiency |

by Testluv » Tue Oct 20, 2009 11:25 pm
Hi Okigbo,
Machine X & Y produce identical bottles at different constant rates. Machine X, operating alone for 4 hours filled part of a production lot; then Machine Y operating alone for 3 hours filled the rest of the lot. How many hours would it take Machine X operating alone to fill the entire lot?

1. Machine X produces 30 bottles / min
2. Machine X produced twice as many bottles in 4 hours as Machine Y produced in 3 hours


From statement 1, we will be able to compute how many bottles X made in 4 hours but will not know how many Y made to complete the task. Hence, we will still not know the quantity of the full lot, and so will be unable to ascertain how long it would take X fill it. Insufficient.

From statement 2, we know that X did two out of three parts of the full job in 4 hours, and hence we would be able to compute how long it would take X to do the entire job (6 hours). Sufficient.

I would choose B.
Join the discussion