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

 It is currently 07 Jul 2015, 09:37

### 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

# In the table above, what is the number of green marbles in J

Author Message
TAGS:
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [0], given: 6761

In the table above, what is the number of green marbles in J [#permalink]  01 Oct 2012, 04:11
Expert's post
3
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

90% (02:18) correct 10% (02:08) wrong based on 352 sessions
Attachment:

Table.png [ 40.01 KiB | Viewed 6527 times ]
In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

Practice Questions
Question: 55
Page: 159
Difficulty: 600
[Reveal] Spoiler: OA

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [1] , given: 6761

Re: In the table above, what is the number of green marbles in J [#permalink]  01 Oct 2012, 04:11
1
KUDOS
Expert's post
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

_________________
Chat Moderator
Joined: 31 Oct 2011
Posts: 521
Schools: Johnson '16 (M)
GMAT 1: 690 Q45 V40
WE: Asset Management (Mutual Funds and Brokerage)
Followers: 36

Kudos [?]: 205 [2] , given: 57

Re: In the table above, what is the number of green marbles in J [#permalink]  01 Oct 2012, 04:19
2
KUDOS
To solve, I took the sum of the expressions as seen below:

X + Y = 80
Y + Z = 120
X + Z = 160
2X + 2Y + 2Z = 360

Dividing by 2 we get X + Y + Z = 180.

Since we know X + Y = 80 from Jar P, we can deduce that Z = 100. Since Z is the number of green marbles in Jar R we have our solution.

[Reveal] Spoiler:

_________________

My Applicant Blog: http://hamm0.wordpress.com/

Director
Joined: 24 Aug 2009
Posts: 507
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 10

Kudos [?]: 468 [1] , given: 241

Re: In the table above, what is the number of green marbles in J [#permalink]  01 Oct 2012, 19:22
1
KUDOS
x+y = 80 ---(1)
x+z = 160---(2)
z+y= 120---(3)
Subtract equation 1 from 2 & we get--> z-y = 80----(4)
Add equation (4) & (3) we get--> 2z= 200
z=100
_________________

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

Intern
Joined: 30 Aug 2011
Posts: 22
Location: United States
Schools: ISB '15
GMAT 1: 680 Q46 V37
WE: Project Management (Computer Software)
Followers: 0

Kudos [?]: 15 [1] , given: 17

Re: In the table above, what is the number of green marbles in J [#permalink]  03 Oct 2012, 23:41
1
KUDOS
x + y = 80 ......(1)
y + z = 120 .....(2)
x + z = 160 ......(3)

From (2) above, z=160-y .....Substitute value of z in (3)

==> x-y = 40 ....(4)

Solve (1) and (4), to get x = 60
==> y = 20
==> z = 100

Thus, number of green marbles in Jar R = 100 (Ans = D)
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [2] , given: 6761

Re: In the table above, what is the number of green marbles in J [#permalink]  04 Oct 2012, 13:20
2
KUDOS
Expert's post
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.
_________________
Manager
Joined: 25 Jun 2012
Posts: 71
Location: India
WE: General Management (Energy and Utilities)
Followers: 2

Kudos [?]: 61 [0], given: 15

Re: In the table above, what is the number of green marbles in J [#permalink]  05 Oct 2012, 02:19
x+y=80...(1)
y+z=120 ==> z=120-y
x+z=160 ==> z=120-x...(3)

120-x=160-y
==> x-y=40...(2)

sloving (1) & (2) we get x=60
put value of x=60 in eqn (3),

60+z=160
=> z=100 Ans
Senior Manager
Joined: 13 Aug 2012
Posts: 464
Concentration: Marketing, Finance
GMAT 1: Q V0
GPA: 3.23
Followers: 17

Kudos [?]: 278 [0], given: 11

Re: In the table above, what is the number of green marbles in J [#permalink]  10 Dec 2012, 03:43
$$x + y = 80$$ eq 1
$$y + z = 120$$ eq 2
$$x + z = 160$$ eq 3
______________
$$2x + 2y + 2z = 360 --> x + y+ z = 180$$ eq 4

Combine eq 4 and eq 1:

$$80 + z = 180 --> z = 100$$

_________________

Impossible is nothing to God.

Senior Manager
Joined: 15 Aug 2013
Posts: 331
Followers: 0

Kudos [?]: 23 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]  13 Apr 2014, 07:52
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?
Manager
Status: suffer now and live forever as a champion!!!
Joined: 01 Sep 2013
Posts: 149
Location: India
GPA: 3.5
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 32 [0], given: 75

Re: In the table above, what is the number of green marbles in J [#permalink]  13 Apr 2014, 20:16
X+Y =80 --------- (1)

Y+Z =120 -------- (2)

X+Z =160 -------- (3)

Subtract (3) -(1)

we get

Z - Y = 80 -----------(4)

Z=100;

Hence D.
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [0], given: 6761

Re: In the table above, what is the number of green marbles in J [#permalink]  14 Apr 2014, 00:30
Expert's post
russ9 wrote:
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.
_________________
Senior Manager
Joined: 15 Aug 2013
Posts: 331
Followers: 0

Kudos [?]: 23 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]  28 Apr 2014, 20:27
Bunuel wrote:
russ9 wrote:
Bunuel wrote:
SOLUTION

In the table above, what is the number of green marbles in Jar R ?

(A) 70
(B) 80
(C) 90
(D) 100
(E) 110

We need to find the value of $$z$$, while given that:

$$x+y=80$$;
$$y+z=120$$;
$$x+z=160$$.

Sum these 3 equations: $$2x+2y+2z=360$$ --> reduce by 2: $$x+y+z=180$$ --> since we know that $$x+y=80$$, then $$80+z=180$$ --> $$z=100$$.

Kudos points given to everyone with correct solution. Let me know if I missed someone.

Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.

Thanks for clarifying.

Just to confirm one of your comments above -- "Yes, we can sum/subtract/multiply equations." -- would this be valid for the problem even if one of the equations didn't have any common variables. What I mean is, if the equations read:

$$x+y=80$$;
$$a+b=120$$;
$$x+z=160$$.

Can we still add the 3?
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [0], given: 6761

Re: In the table above, what is the number of green marbles in J [#permalink]  28 Apr 2014, 23:58
Expert's post
russ9 wrote:
Bunuel wrote:
russ9 wrote:
Are we always allowed to sum the 3 equations? Do we need to have some commonalities to be able to sum the equations?

Yes, we can sum/subtract/multiply equations. I think you are mixing equations with inequalities, for which there are specific rules.

Hope this helps.

Thanks for clarifying.

Just to confirm one of your comments above -- "Yes, we can sum/subtract/multiply equations." -- would this be valid for the problem even if one of the equations didn't have any common variables. What I mean is, if the equations read:

$$x+y=80$$;
$$a+b=120$$;
$$x+z=160$$.

Can we still add the 3?

_______________________
Yes.
_________________
Senior Manager
Joined: 15 Aug 2013
Posts: 331
Followers: 0

Kudos [?]: 23 [0], given: 23

Re: In the table above, what is the number of green marbles in J [#permalink]  29 Apr 2014, 06:47
Bunuel wrote:
russ wrote:

Can we still add the 3?

_______________________
Yes.

Thanks -- that clarifies a lot!
Senior Manager
Joined: 25 Sep 2012
Posts: 277
Location: India
Concentration: Strategy, Marketing
Schools: Ivey '17
GMAT 1: 660 Q49 V31
GMAT 2: 680 Q48 V34
Followers: 0

Kudos [?]: 84 [1] , given: 237

Re: In the table above, what is the number of green marbles in J [#permalink]  29 May 2014, 08:03
1
KUDOS
official answer is not registered for this question.
Math Expert
Joined: 02 Sep 2009
Posts: 28351
Followers: 4485

Kudos [?]: 45451 [0], given: 6761

Re: In the table above, what is the number of green marbles in J [#permalink]  29 May 2014, 08:04
Expert's post
b2bt wrote:
official answer is not registered for this question.

______________
Edited. Thank you.
_________________
Manager
Joined: 12 Feb 2011
Posts: 56
Followers: 0

Kudos [?]: 8 [0], given: 1755

Re: In the table above, what is the number of green marbles in J [#permalink]  20 Aug 2014, 22:47
Another approach can be back solving by taking a value from choices for z and finding x and y to see if they make sense per the table.
SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1859
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 23

Kudos [?]: 970 [0], given: 193

Re: In the table above, what is the number of green marbles in J [#permalink]  09 Sep 2014, 21:05
The table provided in this question was a boon for me. See how below.....
Attachment:

Table.png [ 45.65 KiB | Viewed 2555 times ]

1. Replaced y with (80-x). The equation remains intact on "Jar P" row

2. Copied (80-x) in "Jar Q" row.

These 2 steps directly eliminates x & y

3. Adding rows "Jar Q" & "Jar R"

2z+80 = 280

z = 100

_________________

Kindly press "+1 Kudos" to appreciate

Intern
Joined: 17 Oct 2013
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 19

Re: In the table above, what is the number of green marbles in J [#permalink]  21 Nov 2014, 02:28
From the given table we could make equations like
Equation 1. Given x+y=80 ----> x=80-y
Equation2. Given y+z=120
Equation3. Given x+z = 160
Substituting the value of x in Equation 3 from Equation 1
Equation 4. (80-y)+z=160 ----> -y+z = 80
Adding Equation 2 and Equation 4
2z=200 ---> Z=100.
Re: In the table above, what is the number of green marbles in J   [#permalink] 21 Nov 2014, 02:28
Similar topics Replies Last post
Similar
Topics:
6 The table above shows the distribution of the number 4 27 Mar 2014, 15:56
7 In the table above, what is the least number of table entrie 11 24 Jan 2014, 02:51
6 The table above shows the number of vehicles at Bill's 3 17 Nov 2013, 18:23
4 In the table above what is the least number of table entries 4 15 Mar 2012, 18:59
17 What is the sum of the integers in the table above? 20 06 Apr 2011, 13:21
Display posts from previous: Sort by