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

 It is currently 11 Dec 2013, 23:41

# Events & Promotions

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

Author Message
TAGS:
Intern
Joined: 05 Jul 2010
Posts: 9
Followers: 0

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

00:00

Difficulty:

35% (medium)

Question Stats:

64% (02:36) correct 35% (01:44) wrong based on 131 sessions
At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load?

(A) 1/2
(B) 2/5
(C) 3/5
(D) 4/5
(E) 5/8
[Reveal] Spoiler: OA

Last edited by Bunuel on 26 Sep 2012, 10:56, edited 3 times in total.
Edited the question and added the OA
Math Expert
Joined: 02 Sep 2009
Posts: 15128
Followers: 2534

Kudos [?]: 15619 [3] , given: 1564

Re: Help me with the ANSWER .. Rates + Ratio Question. [#permalink]  07 Oct 2010, 07:21
3
KUDOS
Expert's post
At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load?
(A) 1/2
(B) 2/5
(C) 3/5
(D) 4/5
(E) 5/8

Pick some smart numbers.
Let the day crew has 5 workers and each day crew worker loads 4 boxes, so total boxes loaded by the day crew is 5*4=20;

Then the night crew would have 5*4/5=4 workers and each night crew worker would load 4*3/4=3 boxes, so total boxes loaded by the night crew would be 4*3=12;

Fraction of day crew is 20/(20+12)=20/32=5/8.

_________________
Manager
Joined: 08 Sep 2010
Posts: 238
Location: India
WE 1: 6 Year, Telecom(GSM)
Followers: 3

Kudos [?]: 55 [1] , given: 21

Re: Help me with the ANSWER .. Rates + Ratio Question. [#permalink]  07 Oct 2010, 09:05
1
KUDOS
Just take the Box Loaded by each Night crew is Bn and Box Loaded by each Day Crew is Bd.Then
According to question (Bn)=(3/4)(Bd) i.e (Bn)/(Bd)=3/4

Now again let Night Crew Has Nn number of crew members and Day crew has Nd members.Then according to question (Nn)=(4/5)(Nd) i.e (Nn)/(Nd)=4/5

As number of box carried by the group will be the product of Number of crew multiplied by the number of boxes carried by each member,
According to question we need to find out { (Nd)(Bd) } / { (Nn)(Bn)+(Nd)(Bd) }

Dividing the Nominator and denominator by (Nd)(Bd),

We get, 1 / { (Nn)(Bn)/(Nd)(Bd) + 1 } i.e 1 / { (Nn)/(Nd)*(Bn)/(Bd) + 1 }

i.e 1 / { (3/4)*(4/5) + 1} =5/8

Thanks for a valued Question.

Consider KUDOS if you like the Solution.
Manager
Joined: 27 May 2008
Posts: 128
Followers: 2

Kudos [?]: 19 [0], given: 4

Re: Help me with the ANSWER .. Rates + Ratio Question. [#permalink]  07 Oct 2010, 22:13
its 5/8,
Work done by day crew will be 4x (let x=1), the count of day crew = 5x
Work done by day crew will be 3x (let x=1), the count of day crew = 4x
Total amount work done by both is 5*4+4*3 = 20+12 = 32
Ratio of amount of work done by day crew to total amount of work done is = 20/32 =5/8.
Senior Manager
Joined: 21 Mar 2010
Posts: 317
Followers: 5

Kudos [?]: 18 [0], given: 33

el1981 wrote:
At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all boxes loaded by two crews did the day crew load?
A 1/2
B 2/5
C 3/5
D 4/5
E 5/8

Also, night crew is 4/5th day crew.

Therefore if one day crew member loads x boxes
Night crew is 4/5th of (1 ) * 3/4 = 3/5x

Therefore total number of boxes per crew member (1 night + one day crew) 3/5x +x
= 8/5x.

The x/8/5x = 5/8
Director
Status: -=GMAT Jedi=-
Joined: 04 Jan 2011
Posts: 741
Location: Kochi, India
Schools: ISB
WE 1: Engineer - Larsen & Toubro, ECC Division
WE 2: Faculty - T.I.M.E.
Followers: 29

Kudos [?]: 113 [0], given: 66

Let the number of boxes loaded by each worker in the day crew be x

Then the number of boxes loaded by each worker in the night crew is 3x/4

The number of people in the day crew = y

The number of people in the night crew = 4y/5

Total number of boxes loded:

Day crew = xy

Night crew = 3x/4 * 4y/5 = 3xy/5

Total = xy + 3xy/5 = 8xy/5

Fraction loaded by the day crew = xy/(8xy/5) = 5/8

Ans - 'E'
_________________

Mission: Be a force of good and make a positive difference to every life I touch!

From 650 to 710 to 750 - My Tryst With GMAT [Experience Thread]

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2066
Followers: 119

Kudos [?]: 784 [0], given: 376

scbguy wrote:
at a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load ?

A) 1/2
B)2/5
C)3/5
D)4/5
E)5/8

Please explain the step by step working of this question. Thanks

Say,
Day crew = 5 people
Night crew = (4/5)*5 = 4 people

Each person in day crew loaded = 4 boxes.
Each person in night crew loaded = (3/4)*4= 3 boxes.

Total boxes loaded by day crew = 5*4 = 20
Total boxes loaded by night crew = 4*3 = 12

Fraction of boxes loaded by day crew = 20/(20+12) = 20/32 = 5/8

Ans: "E"
_________________

~fluke

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 3758
Location: Pune, India
Followers: 806

Kudos [?]: 3204 [1] , given: 137

1
KUDOS
Expert's post
scbguy wrote:
at a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load ?

A) 1/2
B)2/5
C)3/5
D)4/5
E)5/8

Please explain the step by step working of this question. Thanks

Workers at night crew loaded 3/4 as many boxes as did day crew so they loaded fewer boxes. Night crew has 4/5 as many workers as the day crew so night crew has fewer workers too. Overall, night crew loaded 3/4 * 4/5 = 3/5 as many boxes as did day crew. So out of a total of 8 boxes, Night Crew loaded 3 and Day Crew loaded 5 so Day Crew loaded 5/8 of total boxes. Or
Boxes loaded by Night Crew: Boxes loaded by Day Crew = 3/5 : 1 = 3:5
So day crew loaded 5/8 of total boxes.

If you are uncomfortable with ratios, check out the following posts. They explain ratios and their applications:
http://www.veritasprep.com/blog/2011/03 ... of-ratios/
http://www.veritasprep.com/blog/2011/03 ... os-in-tsd/
http://www.veritasprep.com/blog/2011/03 ... -problems/

*Didn't see fluke's response there! The concept used is pretty similar.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options. Veritas Prep Reviews Intern Joined: 01 Nov 2010 Posts: 8 Location: United States GMAT Date: 03-30-2012 WE: Pharmaceuticals (Health Care) Followers: 0 Kudos [?]: 6 [0], given: 0 Re: OG12 PS 138- Loading dock and workers [#permalink] 22 Sep 2011, 12:59 Hi, I'm trying to plug in for Question # 138 in OG 12. Could anyone point out where i'm going wrong in my reasoning? I understand the solutions posted in the earlier posts but would like to know where i went wrong. No. of Boxes loaded by Night workers = 3/4 of Day workers No. of Night workers = 4/5 of Day workers. Let the number of Day workers = 100 and they load a total of 100 boxes. No. of boxes loaded by Night workers = 3/4 x 100 = 75 No. of Night workers = 4/5 x 100 = 80 total no. of boxes loaded by both workers = 175 total no. of boxes loaded by day workers = 100 fraction of boxes loaded by day workers out of the total = 100/175 = 4/7 The closest answer is 4/5 which is D. But the correct answer is 5/8 which is E. Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 3758 Location: Pune, India Followers: 806 Kudos [?]: 3204 [0], given: 137 Re: OG12 PS 138- Loading dock and workers [#permalink] 24 Sep 2011, 08:53 Expert's post gmatyro wrote: Hi, I'm trying to plug in for Question # 138 in OG 12. Could anyone point out where i'm going wrong in my reasoning? I understand the solutions posted in the earlier posts but would like to know where i went wrong. No. of Boxes loaded by Night workers = 3/4 of Day workers No. of Night workers = 4/5 of Day workers. Let the number of Day workers = 100 and they load a total of 100 boxes. No. of boxes loaded by Night workers = 3/4 x 100 = 75 No. of Night workers = 4/5 x 100 = 80 total no. of boxes loaded by both workers = 175 total no. of boxes loaded by day workers = 100 fraction of boxes loaded by day workers out of the total = 100/175 = 4/7 The closest answer is 4/5 which is D. But the correct answer is 5/8 which is E. Here is the problem in your solution: It is given that EACH night worker loads 3/4 of the boxes loaded by EACH day worker. (not that total number of boxes loaded by night workers is 3/4 of the boxes loaded by day workers) If I want to take values and I say, each day worker loads 100 boxes, then each night worker loads 75 boxes. Total no of boxes loaded by day workers = 100*100 = 10,000 Total no of boxes loaded by night workers = 80*75 = 6000 Fraction of total boxes loaded by day workers = 10,000/16,000 = 5/8 Though, if I want to take numbers and plug in, I would take easier numbers. Say, there are 5 day workers. Then there are 4 night workers. Say, each day worker loads 4 boxes in a day. Each night worker then loads 3 boxes in a day. Total no of boxes loaded by day workers = 5*4 = 20 Total no of boxes loaded by night workers = 4*3 = 12 Fraction of boxes loaded by day workers = 20/32 = 5/8 _________________ Karishma Veritas Prep | GMAT Instructor My Blog Save$100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Director
Joined: 01 Feb 2011
Posts: 774
Followers: 11

Kudos [?]: 74 [0], given: 42

Night Crew rate = (3/4)* Day Crew rate. -----------------1

Number of night Crew workers = (4/5)*Day crew workers.-------------2

Total Work done by Day crew workers = Number of day crew workers * day crew worker rate.

Total Work done by Night crew workers = Number of night crew workers * night crew worker rate

= (4/5) Day crew workers * (3/4) * Day crew rate

= (3/5)* Total work done by Day crew workers

fraction of all the boxes loaded by the two crews did the day crew load = 1/(1+(3/5)) = 5/8

Senior Manager
Joined: 16 Feb 2012
Posts: 263
Concentration: Finance, Economics
Followers: 4

Kudos [?]: 31 [1] , given: 102

1
KUDOS
I think that the biggest problem for solving this kind of questions is the language understanding (i.e. misunderstanding).
I've had a lot of trouble with this one until I figured out that the night crew did 3/4 and the day crew did 4/4 of the work. And that the night crew had 4/5 workers and the day crew 5/5 workers.
It can become quite messy for a non-native person.
_________________

Kudos if you like the post!

Failing to plan is planning to fail.

Intern
Joined: 15 Nov 2011
Posts: 13
GMAT Date: 03-10-2012
Followers: 0

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

#138 in OG 12 edition problem solving word problem [#permalink]  12 Apr 2012, 18:21
If you don't have the book in front of you the question is:

At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load?
a. 1/2
b. 2/5
c. 3/5
d. 4/5
e. 5/8

I didn't know how to answer this question so I looked at the answer explanations and I still do not understand how to get the answer. The explanation says:

From this, the workers on the night crew will load 3/4(4/5)= 3/5 as many boxes as the day crew. The total loaded by both the day and night crews is thus 1 + 3/4= 5/5 + 3/5= 8/5 of the day crew's work. Therefore, the fraction of all the boxes loaded by the two crews that was done by the day crew was 1/8/5 = 1(5/8) = 5/8.

I understand the first sentence saying that the night crew will load 3/5 as many boxes as the day crew. Where I get mixed up is in the next sentence, The total loaded by both the day and night crews is thus 1 + 3/5 = 5/5 + 3/5 = 8/5 of the day crew's work. I do not understand where the 1 comes from. I am figuring that the number 1 represents the day crew. Is it saying the night crew loads 3/5 as many as the day crew so the day crew loads 5/5? Can someone please explain this to me??

Thanks,

Josh
Senior Manager
Joined: 12 Mar 2012
Posts: 371
Concentration: Operations, Strategy
Followers: 2

Kudos [?]: 80 [0], given: 31

Re: #138 in OG 12 edition problem solving word problem [#permalink]  12 Apr 2012, 19:03
At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load?
a. 1/2
b. 2/5
c. 3/5
d. 4/5
e. 5/8

SEE IT THIS WAY:

night crew loads = 3x/4 boxes/ member

day crew workers= y
night crew workers= 4y/5

total boxes loaded/ day= xy+ (3x/4)*(4y/5)= xy+3xy/5= 8xy/5

required fraction= xy/(8xy/5) = 5/8

Hence E

Hope this clarifies..!!
_________________

Practice Practice and practice...!!

If there's a loophole in my analysis--> suggest measures to make it airtight.

Intern
Joined: 17 Oct 2012
Posts: 28
Location: India
Concentration: Finance, Entrepreneurship
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 7 [0], given: 8

At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many worker as the day crew, what fraction of all the boxes loaded by the two crew did the day crew load.

A) 1/2
B) 2/5
C) 3/5
D) 4/5
E) 5/8

[Reveal] Spoiler:
E
Math Expert
Joined: 02 Sep 2009
Posts: 15128
Followers: 2534

Kudos [?]: 15619 [0], given: 1564

Expert's post
chetan86 wrote:
At a loading dock, each worker on the night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many worker as the day crew, what fraction of all the boxes loaded by the two crew did the day crew load.

A) 1/2
B) 2/5
C) 3/5
D) 4/5
E) 5/8

[Reveal] Spoiler:
E

_________________
Intern
Joined: 09 Jul 2013
Posts: 19
Location: United States
GMAT 1: 570 Q36 V32
GMAT 2: 710 Q44 V44
GPA: 3.65
WE: Military Officer (Military & Defense)
Followers: 0

Kudos [?]: 7 [0], given: 7

I picked some smart numbers and used a table to organize the given information. Just another way to visualize the problem for me...
So, let's say we have 5 day workers. That would give us 4 night workers (4/5 of day). Say the day workers load 12 boxes (I picked a smart-ish number), then the night workers would load 9 boxes (3/4 of what the Day workers load). Put it all in a table and see what you have.

--------- Day ---- Night ----- Total
People---- 5-------- 4------------
Boxes ---- 12 -------9 -----------
Total -----60-------36--------96

I arrived at the Totals on the bottom by multiplying the people and boxes (5x12, 4x9).

So if you want to figure out what fraction of the total the day workers loaded, use:

\frac{60}{96}

This is (number of boxes the day crew loaded) divided by (total number of boxes)

This simplifies to \frac{5}{8}. Thus, E is the answer.

Hope this method helps.
Similar topics Replies Last post
Similar
Topics:
2 At a loading dock, each worker on the night crew loaded 3/4 42 18 May 2006, 13:50
4 At a loading dock, each worker on the night crew loaded 3/4 8 26 Mar 2012, 02:55
A worker can load 1 full truck in 6 hours. A second worker 2 30 Mar 2012, 12:29
Display posts from previous: Sort by