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:

A grocery store sells two varieties of jelly bean jars, and [#permalink]
06 Aug 2011, 03:44

A grocery store sells two varieties of jelly bean jars, and each type of jellybean jar contains only red and yellow jellybeans. If jar B contains 20% more red jellybeans than jar A , but 10% fewer yellow jellybeans, and jar A contains twice as many red jellybeans as yellow jellybeans, by what percent is the number of jellybeans in jar B larger than the number of jellybeans in jar A?

Method 1:

Jar B contains 20% more red jellybeans than jar A but 10% fewer yellow jellybeans

120Rb = 100Ra 90Yb = 100Ya

Jar A contains twice as many red jellybeans as yellow jellybeans

100Ra must be doubled so must be Rb: 240Rb = 200Ra

By what percent is the number of jellybeans in jar B larger than the number of jellybeans in jar A?

Re: A grocery store sells two varieties of jellybean jars... [#permalink]
06 Aug 2011, 05:17

1

This post received KUDOS

1

This post was BOOKMARKED

LGOdream wrote:

A grocery store sells two varieties of jelly bean jars, and each type of jellybean jar contains only red and yellow jellybeans. If jar B contains 20% more red jellybeans than jar A , but 10% fewer yellow jellybeans, and jar A contains twice as many red jellybeans as yellow jellybeans, by what percent is the number of jellybeans in jar B larger than the number of jellybeans in jar A?

\(R_b=1.2R_a\)

\(Y_b=0.9Y_a\)

\(R_a=2Y_a\)

Total in Jar B: \(R_b+Y_b\)

Total in Jar A: \(R_a+Y_a\)

%More in Jar B: \(\frac{Total_{(JarB)}-Total_{(JarA)}}{Total_{(JarA)}}*100\)

%More in Jar B: \(\frac{R_b+Y_b-R_a-Y_a}{R_a+Y_a}*100\)

%More in Jar B: \(\frac{1.2R_a+0.9Y_a-2Y_a-Y_a}{2Y_a+Y_a}*100\)

%More in Jar B: \(\frac{1.2*2*Y_a+0.9Y_a-2Y_a-Y_a}{2Y_a+Y_a}*100=10%\) _________________

Re: A grocery store sells two varieties of jellybean jars... [#permalink]
20 Jan 2012, 03:13

Expert's post

In this kind of problem I'm more comfortable with the chart as suggested in MGMAT Guide 2.....

What I would ask: in this problem we have Jar A Difference and then Jar B if we use the chart. Ok

In other weighted average % change we have for example 2007 and 2008, and then the Total.

But sometimes I put, as in the Jar problem, only Jar A and B and the TOTAL. This is a mistake, because we havve a difference.

How to recognize when we have to use the first or the second. In other words HOW to set a chart in the right way ??' For instance an hint or a word, or a shift in the question stem.

Re: A grocery store sells two varieties of jellybean jars... [#permalink]
20 Jan 2012, 03:46

1

This post received KUDOS

Expert's post

carcass wrote:

In this kind of problem I'm more comfortable with the chart as suggested in MGMAT Guide 2.....

What I would ask: in this problem we have Jar A Difference and then Jar B if we use the chart. Ok

In other weighted average % change we have for example 2007 and 2008, and then the Total.

But sometimes I put, as in the Jar problem, only Jar A and B and the TOTAL. This is a mistake, because we havve a difference.

How to recognize when we have to use the first or the second. In other words HOW to set a chart in the right way ??' For instance an hint or a word, or a shift in the question stem.

I hope is clear what I 'm trying to say.

I'm not sure I understand your question. So can you please give an example (maybe with a chart you are talking about).

As for the question itself: A grocery store sells two varieties of jelly bean jars, and each type of jellybean jar contains only red and yellow jellybeans. If jar B contains 20% more red jellybeans than jar A , but 10% fewer yellow jellybeans, and jar A contains twice as many red jellybeans as yellow jellybeans, by what percent is the number of jellybeans in jar B larger than the number of jellybeans in jar A?

Probably the easiest way would be to pick some smart numbers. As we have fraction of Red/Yellow=2/1 (3 parts) for jar A, then let the number of jellybean in A be 60 (multiple of 3). Then:

Jar A: Red=40 and Yellow=20 --> Total=60; Jar B: Red=40*1.2=48 and Yellow=20*0.9=18 --> Total=66;

Percent=Difference/Original*100=(66-60)/60*100=10% (as we are comparing to Jar A put in denominator total for A).

Re: A grocery store sells two varieties of jelly bean jars, and [#permalink]
20 Jan 2012, 05:03

Expert's post

carcass wrote:

Ok what I mean is this

the first chart is this

The following problem, that is again a weighted average % change problem is this

In the first one I did: Jar A Jar B and then Total NOT Difference. I handle it as the second one. is wrong.

How to recognize in a problem to set a chart as the first one or the second one. I do not see difference but indeed there is difference.

Thanks

The original question asks: "by what percent is the number of jellybeans in B larger than the number of jellybeans in jar A?" Thus we are interested in Difference/Original=Difference/Jar A.

For example by what percent is 14 more than 10: general formula for percent increase or decrease, (percent change): \(Percent=\frac{Change}{Original}*100\) --> \(Percent=\frac{14-10}{10}*100=40%\) --> 14 is 40% more than 10.

The second question: Last year, all registered voters in Kumannia voted either for the Revolutionary Party or for the Status Quo Party. This year, the number of revolutionary voters increased 10%, while the number of Status Que voters increased 5%. No other votes were cast. If the number of total voters increased 8%, what fraction of voters voted Revolutionary this year?

Now, this question asks about the ratio of (This year's Revolutionary voters) to (This year's total voters). So, no percent increase (decrease) involved.

Solution Set the equation for the number of total voters this year: \(1.1R+1.05S=1.08(R+S)\) --> \(2R=3S\)

The question is \(\frac{1.1R}{1.1R+1.05S}=?\) --> \(\frac{1.1R}{1.1R+1.05S}=\frac{110R}{110R+105S}\). Now, as \(2R=3S\) then \(70R=105S\) (multiplying by 35) --> substitute 105S by 70R: \(\frac{110R}{110R+105S}=\frac{110R}{110R+70R}=\frac{11}{18}\)

Re: A grocery store sells two varieties of jelly bean jars, and [#permalink]
30 Oct 2014, 05:40

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. _________________

Low GPA MBA Acceptance Rate Analysis Many applicants worry about applying to business school if they have a low GPA. I analyzed the low GPA MBA acceptance rate at...

http://blog.davidbbaker.com/wp-content/uploads/2015/11/12249800_10153820891439090_8007573611012789132_n.jpg When you think about an MBA program, usually the last thing you think of is professional collegiate sport. (Yes American’s I’m going...

Every student has a predefined notion about a MBA degree:- hefty packages, good job opportunities, improvement in position and salaries but how many really know the journey of becoming...