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:

69% (01:02) correct
31% (01:06) wrong based on 926 sessions

HideShow timer Statistics

At a certain picnic, each of the guests was served either a single scoop or a double scoop of ice cream. How many of the guests were served a double scoop of ice cream?

(1) At the picnic, 60 percent of the guests were served a double scoop of ice cream. (2) A total of 120 scoops of ice cream were served to all the guests at the picnic.

Practice Questions Question: 61 Page: 280 Difficulty: 600

At a certain picnic, each of the guests was served either a single scoop or a double scoop ice-cream. How many of the guests were served a double scoop of ice-cream?

(1) At the picnic, 60 percent of the guests were served a double scoop of ice-cream --> \(\frac{x}{y}=\frac{4}{6}=\frac{2}{3}\), where \(x\) is the # of people served single scoop and \(y\) the # of people served double scoop. Clearly insufficient to calculate single numerical value of \(y\).

(2) A total of 120 scoops of ice-cream were served to all the guests at the picnic --> \(1*x+2*y=120\). Again not sufficient.

(1)+(2) \(x=\frac{2}{3}y\) and \(x+2y=120\): we have 2 distinct linear equations with 2 unknowns, hence we can solve for \(x\) and \(y\). Sufficient. (Just to illustrate: \(\frac{2}{3}y+2y=120\) --> \(y=45\))

Re: At a certain picnic, each of the guests was served either a [#permalink]

Show Tags

15 Oct 2012, 05:12

2

This post received KUDOS

Let the total number of guests be 100x 1) 60x , where x can be anything --->Insufficient 2) Clearly insufficient 1+2) No of guests who are served single scoop = 40x No of guests who are served double scoop = 60x Total no of scoops served - 40x (1) + 60x(2) = 160x Total no of scoops served is 120 Thus 120 = 160x We can get Unique value of 60x which will 60x (120/160) = 45 --->Sufficient

Answer C
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS. Kudos always maximizes GMATCLUB worth-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

Re: At a certain picnic, each of the guests was served either a [#permalink]

Show Tags

15 Oct 2012, 08:57

2

This post received KUDOS

1

This post was BOOKMARKED

1) Only a percentage is given. Nothing can be said from that. 60% of 10 is 6. 60% of 100 is 60 and so on. 2)Only total number of scoops served is given. It can be 50 ppl double scoop, 20 ppl single scoop or 40 ppl double scoop, 40 ppl single scoop and so on.

1 & 2 together

2*.6*x + 1*.4*x = 120

One equation, one unknown. Easily solvable. Hence answer is C

1.6*x = 120

x = 75

So. no. of ppl to whom double scoop was served = .6*75 = 45
_________________

Did you find this post helpful?... Please let me know through the Kudos button.

At a certain picnic, each of the guests was served either a single scoop or a double scoop of ice cream. How many of the guests were served a double scoop of ice cream?

(1) At the picnic, 60 percent of the guests were served a double scoop of ice cream. (2) A total of 120 scoops of ice cream were served to all the guests at the picnic.

Practice Questions Question: 61 Page: 280 Difficulty: 600

Each week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Answer (OA) to them along with a solution.

We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Re: At a certain picnic, each of the guests was served either a [#permalink]

Show Tags

23 Oct 2013, 05:25

What is the problem with my equation? What did I miss? A) Is clearly insufficient But for B) I tried this: 120 = 2*(0,6*x)+1*(0,4*x) With x being the # of people who had ice cream.

What is the problem with my equation? What did I miss? A) Is clearly insufficient But for B) I tried this: 120 = 2*(0,6*x)+1*(0,4*x) With x being the # of people who had ice cream.

You used info given in the first statement for the second statement.
_________________

Re: At a certain picnic, each of the guests was served either a [#permalink]

Show Tags

04 Feb 2014, 18:20

What if there was 100 people at the party, then 60 people get a double scoop (so 120 scoops are given out), and 0 people get single scoops? Based on this my answer was E since the problem states that people are served EITHER a single scoop OR double scoop. How can you answer this question without knowing how many people are at the party?

What if there was 100 people at the party, then 60 people get a double scoop (so 120 scoops are given out), and 0 people get single scoops? Based on this my answer was E since the problem states that people are served EITHER a single scoop OR double scoop. How can you answer this question without knowing how many people are at the party?

This case is not possible because it violates info given in the stem: each of the guests was served either a single scoop or a double scoop ice-cream.

As for the # of the guests, we can get it when we combine the statements: 30 of the guests were served a single scoop of ice-cream; 45 of the guests were served a double scoop of ice-cream.

Concrete value If a Data Sufficiency question asks for the concrete value of one element of a ratio, you will need BOTH the concrete value of another element of the ratio AND the relative value of two elements of the ratio.

Relative value If a Data Sufficiency question asks for the relative value of two pieces of a ratio, ANY statement that gives the relative value of ANY two pieces of the ratio will be sufficient.

We can solve this question using ratios D= # of double-Scoop portions served T= # Total portions served

(1) At the picnic, 60 percent of the guests were served a double scoop of ice cream. This statement tells us that the ratio of D/T = 3/5 Not Sufficient (See explanation above - we are asked to find the concrete Value)

(2) A total of 120 scoops of ice cream were served to all the guests at the picnic. Not sufficient because we need add. a ratio od D/T to answer this question

(1+2) D/S = 3/5 so we have 3x+5x = 120 X = 15 --> D=3*15 =45 (C) Correct, can be calculated, BUT if you know the theory you don't need to calculate by DS Questions, it's enoough to know whether it can be calculated or not.

Hope this helps
_________________

When you’re up, your friends know who you are. When you’re down, you know who your friends are.

Share some Kudos, if my posts help you. Thank you !