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:

If 1/2 of the air in a tank is removed with each stroke of a [#permalink]

Show Tags

24 Jun 2008, 13:16

1

This post received KUDOS

4

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

63% (01:53) correct
37% (00:46) wrong based on 339 sessions

HideShow timer Statictics

If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 4 strokes ?

so first stroke = 1/2 second stroke = 1/4 third stroke = 1/8 fourth stroke = 1/16

8/16 + 4/16 + 2/16 + 1/16 = 15/16

puma wrote:

if 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of the air has been removed after 4 strokes?

A) 15/16 B) 7/8 C) 1/4 D) 1/8 E) 1/16

_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

if 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of the air has been removed after 4 strokes?

If 1/2 of the air in a tank is removed with each stroke of a [#permalink]

Show Tags

09 Jun 2011, 11:26

1

This post received KUDOS

1

This post was BOOKMARKED

If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 4 strokes ?

A. 15/16 B. 7/8 C. 1/4 D. 1/8 E. 1/16

This question is actually from the OG 12th edition. Am not able to understand the explanation given in OG for this problem. Could someone please explain in detail as to how to solve this

Last edited by Bunuel on 24 Sep 2013, 02:43, edited 1 time in total.

Could someone please help me out with the below problem:

If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 4 strokes?

A. 15/16 B. 7/8 C. 1/4 D. 1/8 E. 1/16

This question is actually from the OG 12th edition. Am not able to understand the explanation given in OG for this problem. Could someone please explain in detail as to how to solve this

The best thing to do here is plug in Assume that there is 16 units of air in the tank first stroke = 1/2*16 = 8 ( we are left ith 8 now) second stroke = 1/2*8 = 4( left ith 4 units now) third stoke = 1/2*4 = 2( left with 2 units) 4th stroke = 1/2* 2 = 1 (left with 1 unit)

total units removed = 8+4+2+1 = 15 total unis in the tank at the begining = 16 thus its A . 15/16

Oh, I get it..! Thanks..!!! I think the catch over here is.."the tank is halved after each stroke"....failed to understand the question properly. Thought that a single stoke halves the air in it...so after 2 strokes guessed there wont be any air in it

Let P is 100 ( 1 - 50/100)^4 Remaining amount = 100(1/16)

if 1/16 of 100 is remaining means 1-1/16 = 15/16 is lost. _________________

Piyush K ----------------------- Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. Edison Don't forget to press--> Kudos My Articles: 1. WOULD: when to use?| 2. All GMATPrep RCs (New) Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction".

Re: if 1/2 of the air in a tank is removed with each stroke of a [#permalink]

Show Tags

13 May 2014, 05:31

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Re: If 1/2 of the air in a tank is removed with each stroke of a [#permalink]

Show Tags

13 May 2014, 06:32

1

This post received KUDOS

Expert's post

puma wrote:

If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 4 strokes ?

Re: If 1/2 of the air in a tank is removed with each stroke of a [#permalink]

Show Tags

26 Oct 2015, 10:19

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

So, my final tally is in. I applied to three b schools in total this season: INSEAD – admitted MIT Sloan – admitted Wharton – waitlisted and dinged No...

A few weeks ago, the following tweet popped up in my timeline. thanks @Uber_Mumbai for showing me what #daylightrobbery means!I know I have a choice not to use it...

“This elective will be most relevant to learn innovative methodologies in digital marketing in a place which is the origin for major marketing companies.” This was the crux...