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: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

06 Jan 2011, 06:31

philiptraum wrote:

Thanks for the upload mate!

Quick question on number 4 though:

How many 3-digit numbers satisfy the following conditions: The first digit is different from zero and the other digits are all different from each other?

From my reading of this "the other digits" implies the 2nd and 3rd digits and not the first. Well if only the 2nd and 3rd digits are different from each other then shouldn't it be 9*10*9?

I agree with you on that one. _________________

Thank you for your kudoses Everyone!!!

"It always seems impossible until its done." -Nelson Mandela

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

29 Jan 2011, 08:23

You've heard this 74 times, but it's well worth the 75th.

So, thanks!!! It so happens that I was beginning to wonder how I was going to practice this topic after learning it from the web (considering it is a weak area) and I found this.

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

23 Apr 2011, 02:56

Awesome resource Just one small issue with the secretaries/reports answer, I think there's an error with the OA... 8/9 is clearly too big to be correct

"There are three secretaries who work for four departments. If each of the four departments has one report to be typed out, and the reports are randomly assigned to a secretary, what is the probability that all three secretaries are assigned at least one report? "

There are 3^4 (or 3*3*3*3) possible combinations = each option therefore is 1/81.

You then choose 1 of three secretaries (3C1) to receive two reports (4C2), and then work out the number of permutations to assign the remaining 2 reports to the 2 remaining secretaries (2P2).

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

28 Apr 2011, 09:04

In the second file, the solution for Q32 is wrong. The correct answer should be 171. The total number of diagonals is 21x18/2=189 and from this, one has to remove the number of diagonals from one vertex, i.e. 189-18=171. To the two adjacent vertices to the one which doesn't send any, there are still 18 diagonals connected to. When working out the number of the diagonals one should take into account the definition of a diagonal - a line segment which connects two non-adjacent vertices. So, any vertex, connects to n-3 different vertices (not to itself, and not to the two adjacent vertices).

Question 33 is not properly formulated, because the answer depends on how the three vertices relate to each other. Of course the solution is wrong, due to the same mistake made for the previous question. So, one should ask the question how many diagonals are in a polygon with 18 vertices in which three adjacent vertices don't send any. And the correct answer is 91. _________________

PhD in Applied Mathematics Love GMAT Quant questions and running.

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

09 Sep 2011, 23:54

Some of the Answers are wrong in this document. Heres One

20. In a flower shop, there are 5 different types of flowers. Two of the flowers are blue, two are red and one is yellow. In how many different combinations of different colors can a 3-flower garland be made?

a) 4. b) 20. c) 3. d) 5. e) 6.

According to the document

20. The best answer is A. We want to make a 3-flower garlands, each should have three colors of flowers in it. There are two different types of blue and two different types of red. The options are (2 blue) x (2 red) x (1 yellow) = 4 options.

According to me

answer should be 5 because it according the the question it is not compulsory to have 3 colors ! it asks for a number of different combinations i see the following as combination

1) 2Red + 1 Blue 2) 2red+1 yellow 3)1 yellow+1 blue+ 1 red 4) 2 blue+ 1 yellow 5) 2 blue + 1 red

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

10 Sep 2011, 00:57

26. What is the probability for a family with three children to have a boy and two girls (assuming the probability of having a boy or a girl is equal)?

a) 1/8 b) ¼ c) ½ d) 3/8 e) 5/8

26. The best answer is D. There are three different arrangements of a boy and two girls:(boy, girl, girl), (girl, boy, girl), (girl, girl, boy). Each has a probability of (1/2)3. The total is 3*(1/2)3=3/8.

WHY DOES THE ORDER MATTER IN THIS QUESTION. I MEAN THEY HAVE A BOY AND 2 GIRLS SHOULD NOT IT JUST BE 3/8?

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

27 Dec 2011, 22:41

The answer to question 40 does not seem right to me. Shouldn't the answer be 48? The question is as follows. A computer game has five difficulty levels. In each level you can choose among four different scenarios except for the first level, where you can choose among three scenarios only. How many different games are possible?

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

27 Mar 2012, 12:18

cmal1985 wrote:

26. What is the probability for a family with three children to have a boy and two girls (assuming the probability of having a boy or a girl is equal)?

a) 1/8 b) ¼ c) ½ d) 3/8 e) 5/8

26. The best answer is D. There are three different arrangements of a boy and two girls:(boy, girl, girl), (girl, boy, girl), (girl, girl, boy). Each has a probability of (1/2)3. The total is 3*(1/2)3=3/8.

WHY DOES THE ORDER MATTER IN THIS QUESTION. I MEAN THEY HAVE A BOY AND 2 GIRLS SHOULD NOT IT JUST BE 3/8?

What about the possibility of 3 boys or 3 girls ? Here, I think the order does not matter. the possibilities are - 3Boys, 2Boys-1Girl, 1boy-2girls, 3Girls. so out of 4 possible outcomes, the probability of 1boy-2girls is 1/4.

Re: Permutations, Combinations, Probability - Download Questions [#permalink]

Show Tags

16 Feb 2014, 08:02

1

This post received KUDOS

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. _________________

Check out this awesome article about Anderson on Poets Quants, http://poetsandquants.com/2015/01/02/uclas-anderson-school-morphs-into-a-friendly-tech-hub/ . Anderson is a great place! Sorry for the lack of updates recently. I...

As you leave central, bustling Tokyo and head Southwest the scenery gradually changes from urban to farmland. You go through a tunnel and on the other side all semblance...