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
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
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
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.

130-point 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.

rates and formulae.

Expert replies
by ildude02 » Sun Jul 13, 2008 7:37 am
A's rate is twice that of B and 1/3 that of C. They all combined to produce 2700 units, how many units did C produce?

a)300
b)600
c)900
d)1200
e)1800

My question is, I always get confused when to sum them all up and equate to the total and when we should use the formulae; 1/A +1/B +1/C = 1/T; where T is the total time, and then you derive the units based off the individual time. Can someone clarify this for me? Thanks!
Join the discussion
Source: — Problem Solving |

by raunekk » Sun Jul 13, 2008 8:44 am
IMO:E (1800)

IF you are given total time taken to do a job by a person or a machine,

then you need to use the formula 1/a+1/b.This will give you work done per-hour by each machine individually.That is, rate.

But if u are directly given time or rate/hour of each component you dont need to use that formula..you can directly use w=rt.

This is what you are asking rite??
Join the discussion

by ildude02 » Sun Jul 13, 2008 8:48 am
So you just add them up to get 9x and find x instead of using the formula?

Also, isn't there a formuale for even units along with time?

Units of A/TimeA + Unites B/TimeB = Total Units/TotalTime; when do we use this formulae? If we are given indivdual times and units produced by each of them and asked to find the missing units?

Appreciate your response.
Join the discussion

by sudhir3127 » Sun Jul 13, 2008 9:18 am
answer is E 1800..

A+A/2+3A= 2700

A=600
hence C= 1800
Join the discussion