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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Work related

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Tue Apr 07, 2009 8:26 pm
Location: India
by rkhicha » Wed Jul 14, 2010 8:09 am
Q. If A&B can do a particular task in 15 hours, B&C can do the same task and 12 hours and A&C can complete it in 60/7 hours. How many hours will it take for A, B & C to complete it?

Thanks.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pmFollowed by: 7 members
Thanked: 215 times

by kvcpk » Wed Jul 14, 2010 8:13 am
rkhicha wrote:Q. If A&B can do a particular task in 15 hours, B&C can do the same task and 12 hours and A&C can complete it in 60/7 hours. How many hours will it take for A, B & C to complete it?

Thanks.
Assume there is 420 units of work

A+B will do 420/15 = 28 units per hour
B+C will do 420/12 = 35 units per hour
C+A will do 420/60/7 = 49 units per hour
Sum of all is 112
112/2 will give A+B+C= 56 units per hour.

Hence they will finish in 420/56 = 60/8=30/4 = 7.5 hours.

Hope this helps!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 294
Joined: Wed May 05, 2010 4:01 am
Location: india
Thanked: 57 times

by amising6 » Wed Jul 14, 2010 8:14 am
rkhicha wrote:Q. If A&B can do a particular task in 15 hours, B&C can do the same task and 12 hours and A&C can complete it in 60/7 hours. How many hours will it take for A, B & C to complete it?

Thanks.
If A&B can do a particular task in 15 hours
A&B can do 1/15 of particular task in 1 hr
B&C can do the same task and 12 hours
B&C can do the 1/12 of same task in 1hours
A&C can complete it in 60/7 hours
A&C can complete7/60 of work in 1 hr

so adding 2(a+b+c) can complete 1/15+1/12+7/60 in 1 hour

2(a+b+c)=16/60 of work in 1 hr
a+b+c will complete 2/15 of work in 1 hr
so a+b+c will complete full wotk in 1/2/15=15/2 hrs
Ideation without execution is delusion
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 1052
Joined: Fri May 21, 2010 1:30 amFollowed by: 98 members
Thanked: 335 times

by Patrick_GMATFix » Wed Jul 14, 2010 10:08 am
kvcpk wrote:
rkhicha wrote:Q. If A&B can do a particular task in 15 hours, B&C can do the same task and 12 hours and A&C can complete it in 60/7 hours. How many hours will it take for A, B & C to complete it?

Thanks.
Assume there is 420 units of work

A+B will do 420/15 = 28 units per hour
B+C will do 420/12 = 35 units per hour
C+A will do 420/60/7 = 49 units per hour
Sum of all is 112
112/2 will give A+B+C= 56 units per hour.

Hence they will finish in 420/56 = 60/8=30/4 = 7.5 hours.

Hope this helps!!
Very nice solution
  • Ask me about tutoring.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pmFollowed by: 7 members
Thanked: 215 times

by kvcpk » Wed Jul 14, 2010 10:10 am
Patrick_GMATFix wrote:
Hope this helps!!
Very nice solution[/quote]

Thanks Patrick!! :)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1