Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 07 Jul 2015, 19:28

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# For each positive integer k, the quantity

Author Message
Math Expert
Joined: 02 Sep 2009
Posts: 28352
Followers: 4487

Kudos [?]: 45492 [1] , given: 6762

For each positive integer k, the quantity [#permalink]  07 May 2013, 01:13
1
KUDOS
Expert's post
1. For each positive integer k, the quantity $$x_k$$ is defined such that $$x_k = x_{k+1} * ( x_{k+2})^3$$

In addition, $$x_3 = 1$$. In the table, select values for $$x_1$$ and $$x_4$$ that are jointly compatible with these conditions. Select only two values, one in each column.

$$x_1$$ -- $$x_4$$
------------------------------- 0
------------------------------- 2
------------------------------- 5
------------------------------- 8
------------------------------- 16
------------------------------- 64
_________________
Manager
Status: *Lost and found*
Joined: 25 Feb 2013
Posts: 123
Location: India
Concentration: General Management, Technology
GMAT 1: 640 Q42 V37
GPA: 3.5
WE: Web Development (Computer Software)
Followers: 15

Kudos [?]: 84 [1] , given: 14

Re: For each positive integer k, the quantity [#permalink]  07 May 2013, 10:07
1
KUDOS
Bunuel wrote:
1. For each positive integer k, the quantity $$x_k$$ is defined such that $$x_k = x_{k+1} * ( x_{k+2})^3$$

In addition, $$x_3 = 1$$. In the table, select values for $$x_1$$ and $$x_4$$ that are jointly compatible with these conditions. Select only two values, one in each column.

$$x_1$$ -- $$x_4$$
------------------------------- 0
------------------------------- 2
------------------------------- 5
------------------------------- 8
------------------------------- 16
------------------------------- 64

From the above it can be deduced, that x1 = x2 = (x4)^3. Hence, for values of x1, x4 only 2,8 satisfy the same. If the above values apply, I believe the expression x-k cannot be said always an integer. since x-5 = (1/2)^(1/3). But since the question mentions it a 'quantity', it seems that fits the question as well.

Please correct me if I am wrong

Regards,
Arpan
_________________

Feed me some KUDOS! *always hungry*

Manager
Joined: 11 Jun 2010
Posts: 84
Followers: 0

Kudos [?]: 11 [0], given: 17

Re: For each positive integer k, the quantity [#permalink]  16 May 2013, 19:18
X3 = 1
therefore x1=x2*1 or x1=x2 and
x2 = 1*(x4)^3
X1 = (x4)^3
only combinations for x1 and x4 where x1 can be cube of x4 is 8 for x1 and 2 for x4

And X1 = 8 / X4 = 2
Re: For each positive integer k, the quantity   [#permalink] 16 May 2013, 19:18
Similar topics Replies Last post
Similar
Topics:
Number of questions for each IR question type 1 21 Nov 2014, 18:49
For integers, x and y, x=y+2. From the table below 1 06 Jul 2014, 04:45
5 Twenty-five adults reported the amount of time each spent st 4 08 May 2013, 06:02
For each of the following statements, select True if the 9 08 May 2013, 05:54
3 Each of the variables X, Y, and Z can only be 0 or 1. The 6 30 Sep 2012, 04:16
Display posts from previous: Sort by