Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: Three hoses, x, y, and z, each pump water at a constant rate. How long [#permalink]

Show Tags

17 Mar 2017, 10:13

Each statement alone is insufficient. But in (I) its given that each of them ie x and z pumps at 120 gallons/hr. (II) says y pumps half the rate of x which is 60 gallons /hr. Isn't combining both sufficient to find how long it takes to fill the tank ?

Three hoses, x, y, and z, each pump water at a constant rate. How long [#permalink]

Show Tags

21 Mar 2017, 20:52

I'm not sure about this one. The answer could be C if we can assume that all of the hoses started at the same time. But that is not explicitly stated. So, I think the answer is E.

R x T = W X 120 g/hr Y 60 g/hr Z 120 g/hr

(120+120+60) x T = 30K this can be solved or 120*t_x + 120*t_z + 60*t_y = 30K this can't be solved

Re: Three hoses, x, y, and z, each pump water at a constant rate. How long [#permalink]

Show Tags

23 Mar 2017, 04:28

Option C

I: No information about pumping rate of hose Y: Insufficient

II: Pumping rate X = 2 * (Pumping rate Y) No information on pumping rates. Insufficient

I + II: Pumping rate of all three hoses can be obtained. Assuming all three hoses pump for same duration of time (unless stated otherwise), the time required to fill tank of any volume can be estimated.
_________________

We're told that 3 pumps each pump water at a constant rate. We're asked how long it would take to fill up a 30,000 gallon tank.

If we're meant to assume that the tank starts off 'empty', then this is a relatively straight-forward prompt (we need the rates of the 3 pumps to answer the question).

1) Hoses X and Z each pump water at constant rate of 120 gallons per hour.

This Fact tells us nothing about the rate of Hose Y, so the answer will vary depending on that rate. Fact 1 is INSUFFICIENT

2) Hose Y pumps water at half the rate of X.

This Fact tells us nothing about any of the rates, so the answer will vary depending on those rates. Fact 2 is INSUFFICIENT

Combined, we know.... Hose X = 120 gallons/hour Hose Z = 120 gallons/hour Hose Y = 60 gallons/hour

We can now calculate how long it would take to pump 30,000 gallons of water. Again, if we're meant to assume that the tank starts off empty, then this information is SUFFICIENT. IF there's some water in the tank though, then the information is INSUFFICIENT (we would need to know the exact volume of water that needs to be pumped).