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
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
Start free 5-day trial
Read 559 reviewsTarget Test Prep

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

Pipe leak

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 435
Joined: Mon Mar 15, 2010 6:15 amFollowed by: 1 member
Thanked: 32 times
by eaakbari » Sun Apr 11, 2010 10:17 pm
A leak in the bottom of a tank can empty the full tan in 8 hr. An inlet pipe fills water at the rate of 6 lits a minute. When the tank is full,the inlet is opened and due to the leak, the tank is empty in 12 hrs.How many liters does the cistern hold?



Source: prep review book
Whether you think you can or can't, you're right.
- Henry Ford
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Legendary Member
Posts: 576
Joined: Sat Mar 13, 2010 8:31 pmFollowed by: 1 member
Thanked: 97 times

by liferocks » Sun Apr 11, 2010 10:30 pm
consider the cistern holds 800x liters of water
so the leak empties 100x/hr and the pipe fills 6*60=360L/hr
so the full tank will be empty in
800x/(100x-360) hr which is 12
solving this we get the capacity of the cistern is 8640 liters
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Sun Apr 11, 2010 10:44 pm
eaakbari wrote:A leak in the bottom of a tank can empty the full tank in 8 hr. An inlet pipe fills water at the rate of 6 lits a minute. When the tank is full,the inlet is opened and due to the leak, the tank is empty in 12 hrs.How many liters does the cistern hold?



Source: prep review book
Let V lit. be the vol of tank .
so due to leak total volume which came out = (12/8) * V = (3/2)*V lit.
vol. filled by inlet pipe = 6 * 60 * 12 lit.
so 6 * 60 * 12 + V = (3/2)*V --> (1/2)* V = 6 * 60 * 12 --> V = 6*60*12*2 lit. = 8640 lit.
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 435
Joined: Mon Mar 15, 2010 6:15 amFollowed by: 1 member
Thanked: 32 times

by eaakbari » Mon Apr 12, 2010 2:21 am
Work done by the inlet in 1 hr= 1/8 -1/12=1/24
Work done by the inlet in i min= (1/24)*(1/60)=1/1440
Therefore, Volume of 1/1440 part=6 lit
Volume of whole=(1440*6) lit=8640 lit.
Whether you think you can or can't, you're right.
- Henry Ford
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 526
Joined: Sat Feb 21, 2009 11:47 pm
Location: India
Thanked: 68 times
GMAT Score:680

by harshavardhanc » Mon Apr 12, 2010 5:01 am
eaakbari wrote:A leak in the bottom of a tank can empty the full tan in 8 hr. An inlet pipe fills water at the rate of 6 lits a minute. When the tank is full,the inlet is opened and due to the leak, the tank is empty in 12 hrs.How many liters does the cistern hold?



Source: prep review book
Leak does a -ve work of 12.5 %(1/8), but due to the inlet pipe the -ve becomes 8.33% (1/12)

or the inlet pipe is doing a +ve work of 12.5 - 8.33 = 4.166 % OR 1/24

Therefore, the inlet pipe fills the tank in 24 hrs. Hence, the quantity in 24 hrs = 24 * 60 * 6 = 8640 lts.
Regards,
Harsha
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Sat May 19, 2007 8:59 am
Thanked: 1 times

by samirnajeeb » Sun Jan 02, 2011 1:39 am
a leak can empty in 8 hrs but it took 12 hrs to empty ... so it basically emptied 1.5 tank
thus, 0.5 tank was filled by inlet pipe

rate of inlet pipe = 360 ltr/hr
in 12 hrs = 360*12 lts

capacity of tank is double of what inlet pipe emptied = 360*12*2 = 8640 ltrs
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Sun Jan 02, 2011 4:13 am
eaakbari wrote:A leak in the bottom of a tank can empty the full tan in 8 hr. An inlet pipe fills water at the rate of 6 lits a minute. When the tank is full,the inlet is opened and due to the leak, the tank is empty in 12 hrs.How many liters does the cistern hold?

Source: prep review book
The GMAT would provide answer choices, which we could plug in for the volume of the cistern. The correct answer likely would be divisible by 8 and 12.

Answer choice: volume = 8640 liters
Rate of leak = w/t = 8640/8 = 1080 liters per hour.
Rate of inlet = 6 liters per minute = 360 liters per hour.
Combined rate to empty the tank = leak-inlet = 1080-360 = 720 liter per hour.
Time to empty the tank = w/r = 8640/720 = 12 hours. Success!

The correct answer is 8640 liters.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1