It is currently 10 Dec 2017, 19:26

Close

GMAT Club Daily Prep

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A lunar mission is made up of x astronauts and is formed from a total

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42529

Kudos [?]: 135163 [0], given: 12664

A lunar mission is made up of x astronauts and is formed from a total [#permalink]

Show Tags

New post 17 Aug 2017, 00:56
Expert's post
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

44% (01:39) correct 56% (02:12) wrong based on 33 sessions

HideShow timer Statistics

A lunar mission is made up of x astronauts and is formed from a total of 12 astronauts. A day before the launch the commander of the program decides to add p astronauts to the mission. If the total number of possible lunar missions remain unchanged after the commander’s decision, then which of the following cannot be the value of p?

(A) x
(B) x + 3
(C) 3
(D) 6
(E) 8
[Reveal] Spoiler: OA

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135163 [0], given: 12664

Expert Post
1 KUDOS received
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5333

Kudos [?]: 6082 [1], given: 121

Re: A lunar mission is made up of x astronauts and is formed from a total [#permalink]

Show Tags

New post 17 Aug 2017, 20:42
1
This post received
KUDOS
Expert's post
Bunuel wrote:
A lunar mission is made up of x astronauts and is formed from a total of 12 astronauts. A day before the launch the commander of the program decides to add p astronauts to the mission. If the total number of possible lunar missions remain unchanged after the commander’s decision, then which of the following cannot be the value of p?

(A) x
(B) x + 3
(C) 3
(D) 6
(E) 8




Hi...

I take it that these p too are selected from existing 12 ..

When you make a team, you are actually dealing with COMBINATIONS..
So you can choose x out of 12 in 12Cx ways..
You can choose x+p out of 12 in 12C(x+p)..
But the # of missions are same so 12Cx=12C(x+p)..

But nCx=nC(n-x)..
So 12Cx=12C(12-x)=12C(x+p)...
So 12-x=x+p.....12=2x+p..
So p=12-2x=2(6-x)..
So our answer has to be an EVEN number..
ONLY C is odd..
Ans C..

Otherwise you can solve it ..
12=2x+P..
x=1, p=10
X=2, p=8..... Choice E
X=3, P=6..... Nothing but choice B. p=x+3....Also choice D
X=4, P=4..... Nothing but choice A. x=p
X=5, p=2

Only C that is 3 is not there

C
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 6082 [1], given: 121

Manager
Manager
avatar
B
Joined: 11 Feb 2017
Posts: 174

Kudos [?]: 10 [0], given: 198

A lunar mission is made up of x astronauts and is formed from a total [#permalink]

Show Tags

New post 18 Aug 2017, 01:13
Bunuel wrote:
A lunar mission is made up of x astronauts and is formed from a total of 12 astronauts. A day before the launch the commander of the program decides to add p astronauts to the mission. If the total number of possible lunar missions remain unchanged after the commander’s decision, then which of the following cannot be the value of p?

(A) x
(B) x + 3
(C) 3
(D) 6
(E) 8


I tried to solve it but Im not sure if I am right or not

Total = 12

so teams can be made as such
2 2 2 2 2 2 here x= 2
3 3 3 3 here x= 3
4 4 4 here x= 4
6 6 here x= 6

If p members are added then what CANT BE P?

1) x , so we need to put p= x ,

if we take x = 2 then p=2 cant be distributed equally among team of 2 as we need 6 members to add one in every team to keep same number of teams

if we take x = 3 then p=3 cant be distributed equally among team of 3 as we need 4 members to add one in every team to keep same number of teams

if we take x = 4 then p=4 cant be distributed equally among team of 4 as we need 3 members to add one in every team to keep same number of teams

if we take x = 6 then p=6 CAN be distributed equally among team of 6 as we need 2 members to add one in every team to keep same number of teams and we can distribute 6 members in 2 teams


2) x + 3 , so we need to put p = x+3 ,

if we take x = 2 then p=5 cant be distributed equally among team of 2 as we need 6 members to add one in every team to keep same number of teams

if we take x = 3 then p=6 cant be distributed equally among team of 3 as we need 4 members to add one in every team to keep same number of teams

if we take x = 4 then p=7 cant be distributed equally among team of 4 as we need 3 members to add one in every team to keep same number of teams

if we take x = 6 then p=9 cant be distributed equally among team of 6 as we need 2 members to add one in every team to keep same number of teams

3) p = 3

3 members can be divided equally when x = 4

4) p = 6

6 members can be divided equally when x= 2

5) p = 8

8 members can be divided equally when x= 3


SO ONLY B don't have all possible ways in which p can be equally divided .

B answer

Kudos [?]: 10 [0], given: 198

Manager
Manager
avatar
B
Joined: 11 Feb 2017
Posts: 174

Kudos [?]: 10 [0], given: 198

Re: A lunar mission is made up of x astronauts and is formed from a total [#permalink]

Show Tags

New post 18 Aug 2017, 01:19
chetan2u wrote:
Bunuel wrote:
A lunar mission is made up of x astronauts and is formed from a total of 12 astronauts. A day before the launch the commander of the program decides to add p astronauts to the mission. If the total number of possible lunar missions remain unchanged after the commander’s decision, then which of the following cannot be the value of p?

(A) x
(B) x + 3
(C) 3
(D) 6
(E) 8


can u plz look at my solution above and tell me what I have done wrong?

Kudos [?]: 10 [0], given: 198

Expert Post
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5333

Kudos [?]: 6082 [0], given: 121

Re: A lunar mission is made up of x astronauts and is formed from a total [#permalink]

Show Tags

New post 18 Aug 2017, 02:40
rocko911 wrote:
chetan2u wrote:
Bunuel wrote:
A lunar mission is made up of x astronauts and is formed from a total of 12 astronauts. A day before the launch the commander of the program decides to add p astronauts to the mission. If the total number of possible lunar missions remain unchanged after the commander’s decision, then which of the following cannot be the value of p?

(A) x
(B) x + 3
(C) 3
(D) 6
(E) 8


can u plz look at my solution above and tell me what I have done wrong?


Hi..
There is a problem in understanding of the problem.
Although not very clearly mentioned, the wordings do point towards..
There are 12 astronauts. A team of x will be send on a mission. If P more astronauts are added on a mission, now totalling x+p, and the number of missions possible remain the same.
It has to mean this because otherwise if 12 is added in group of x, and then in x+p, the number of group can NEVER be the same.
Example 12 divided with 4in each group makes 3group so if you add 1 more , the number of groups can never be 4.

But in the given Q, you have to find the combinations of x astronauts and x+P astronauts when TOTAL is 12...
So 12Cx=12C(x+P)..
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 6082 [0], given: 121

Re: A lunar mission is made up of x astronauts and is formed from a total   [#permalink] 18 Aug 2017, 02:40
Display posts from previous: Sort by

A lunar mission is made up of x astronauts and is formed from a total

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.