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:

Official Answer and Stats are available only to registered users. Register/Login.

_________________

Don't give up on yourself ever. Period. Beat it, no one wants to be defeated (My journey from 570 to 690): http://gmatclub.com/forum/beat-it-no-one-wants-to-be-defeated-journey-570-to-149968.html

Last edited by Bunuel on 14 Dec 2012, 09:26, edited 1 time in total.

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Re: The average of 6 numbers in a set is equal to 0. What is the [#permalink]

Show Tags

14 Dec 2012, 09:58

Bunuel wrote:

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Answer: E.

If "Each of the positive numbers in the set equals 10" and "Each of the negative numbers in the set equals -5", don't you think we have gotten our answer?
_________________

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Answer: E.

If "Each of the positive numbers in the set equals 10" and "Each of the negative numbers in the set equals -5", don't you think we have gotten our answer?

I don't understand your question.

Solution gives two possible sets which give two different answers to the question. Therefore the answer is E.
_________________

Re: The average of 6 numbers in a set is equal to 0. What is the [#permalink]

Show Tags

14 Dec 2012, 10:22

Bunuel wrote:

knightofdelta wrote:

Bunuel wrote:

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Answer: E.

If "Each of the positive numbers in the set equals 10" and "Each of the negative numbers in the set equals -5", don't you think we have gotten our answer?

I don't understand your question.

Solution gives two possible sets which gives two different answers to the question. Therefore the answer is E.

It seems like combining (1) and (2) will only provide the first set in your solution i.e. {-5, -5, -5, -5, 10, 10}. Where did you get the zeros in {-5, -5, 0, 0, 0, 10} when each of the negative number is -5 and each of the positive number is 10?
_________________

If "Each of the positive numbers in the set equals 10" and "Each of the negative numbers in the set equals -5", don't you think we have gotten our answer?

I don't understand your question.

Solution gives two possible sets which gives two different answers to the question. Therefore the answer is E.

It seems like combining (1) and (2) will only provide the first set in your solution i.e. {-5, -5, -5, -5, 10, 10}. Where did you get the zeros in {-5, -5, 0, 0, 0, 10} when each of the negative number is -5 and each of the positive number is 10?

Zero is neither negative nor positive number.

Now consider {-5, -5, 0, 0, 0, 10}: each of the positive numbers in the set equals 10 and each of the negative numbers in the set equals –5.

Re: The average of 6 numbers in a set is equal to 0. What is the [#permalink]

Show Tags

02 Sep 2014, 14:16

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: The average of 6 numbers in a set is equal to 0. What is the [#permalink]

Show Tags

29 Jul 2015, 16:08

Bunuel wrote:

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Answer: E.

Hi Bunnuel,

I got C. Here is my explanation

(Sum of + numbers)+(Sum of - numbers) = 6

0 = [(Sum of + numbers)+(Sum of 0 numbers)][/6] 0 = (Sum of + numbers)+(Sum of - numbers)

From 1. (Sum of + numbers) = 10*(Quantity of + numbers)

From 2. (Sum of - numbers) = 10*(Quantity of - numbers)

The average of 6 numbers in a set is equal to 0. What is the number of positive numbers in the set minus the number of negative numbers in the set?

Since the average of 6 numbers in the set is equal to 0, then the sum of 6 numbers is also 0. Which means that the sum of the negative numbers must compensate the sum of the positive numbers.

(1) Each of the positive numbers in the set equals 10. Not sufficient. (2) Each of the negative numbers in the set equals –5. Not sufficient.

(1)+(2) The number of negative numbers (-5) must be twice the number of positive numbers (10). Possible cases are {-5, -5, -5, -5, 10, 10} and {-5, -5, 0, 0, 0, 10}. Thus the number of positive numbers minus the number of negative numbers could be either -2 or -1. Not sufficient.

Answer: E.

Hi Bunnuel,

I got C. Here is my explanation

(Sum of + numbers)+(Sum of - numbers) = 6

0 = [(Sum of + numbers)+(Sum of 0 numbers)][/6] 0 = (Sum of + numbers)+(Sum of - numbers)

From 1. (Sum of + numbers) = 10*(Quantity of + numbers)

From 2. (Sum of - numbers) = 10*(Quantity of - numbers)

Can you explain where i made my mistake? Thanks.

Not sure that I completely understand your approach but I think that you missed that there could be some number of zeros in the set. Check the highlighted part for possible sets, proving E.
_________________

Re: The average of 6 numbers in a set is equal to 0. What is the [#permalink]

Show Tags

01 Mar 2017, 17:20

Since the average of the 6 numbers in a set is 0, the sum of the 6 numbers is 0. We also know there could be positive numbers and negative numbers in the set. Zero is not mentioned, but this does not rule it out. In order for the sum of the numbers in the set to be 0, either all the terms are 0, or there are some positives and some negatives.

(1) INSUFFICIENT: Statement 1 tells us that the set has at least one positive number, and that each positive term is 10. We should try to prove insufficiency. For instance, the set could be {–2, –2, –2, –2, –2, 10}, and the number of positive terms minus the number of negative terms would be 1 – 5 = –4. Alternatively, the set could be {–20, –20, 10, 10, 10, 10}, and the answer would be 4 – 2 = 2.

(2) INSUFFICIENT: Statement 2 tells us that the set has at least one negative number, and that each negative term is –5. Again, we should try to prove insufficiency. The set could be {–5, 1, 1, 1, 1, 1}, and the number of positive terms minus the number of negative terms would be 5 – 1 = 4. The set could be {–5, –5, –5, 2, 5, 8}, and the answer would be 3 – 3 = 0.

(1) & (2) INSUFFICIENT: The statements together suggest that the set has twice as many –5 terms as 10 terms, in order to maintain a sum of 0. If every term is negative or positive, then the set would have to be {–5, –5, –5, –5, 10, 10} and the definitive answer would be 2 – 4 = –2. However, zero terms are possible, so the set could be {–5, –5, 0, 0, 0, 10} and an alternative answer would be 1 – 2 = –1.

Version 8.1 of the WordPress for Android app is now available, with some great enhancements to publishing: background media uploading. Adding images to a post or page? Now...

Post today is short and sweet for my MBA batchmates! We survived Foundations term, and tomorrow's the start of our Term 1! I'm sharing my pre-MBA notes...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...