It is currently 15 Dec 2017, 13:38

# Decision(s) Day!:

CHAT Rooms | Olin (St. Louis) R1 | Tuck R1 | Ross R1 | Fuqua R1

### 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

# John and Mary were each paid x dollars in advance to do a

Author Message
TAGS:

### Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 178

Kudos [?]: 3655 [3], given: 0

John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

27 Dec 2012, 05:05
3
KUDOS
34
This post was
BOOKMARKED
00:00

Difficulty:

65% (hard)

Question Stats:

58% (02:10) correct 42% (02:25) wrong based on 998 sessions

### HideShow timer Statistics

John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y
[Reveal] Spoiler: OA

Kudos [?]: 3655 [3], given: 0

Math Expert
Joined: 02 Sep 2009
Posts: 42618

Kudos [?]: 135755 [21], given: 12708

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

27 Dec 2012, 05:07
21
KUDOS
Expert's post
20
This post was
BOOKMARKED
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

The amount Mary has in the end is x-y dollars and she worked for 8 hours;
The amount John has in the end is x+y dollars and he worked for 10 hours;;

We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$.

_________________

Kudos [?]: 135755 [21], given: 12708

Intern
Joined: 09 Sep 2013
Posts: 16

Kudos [?]: 2 [0], given: 7

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

18 Oct 2013, 15:30
Could someone also do this problem plugging numbers. I tried but it is not working.

Kudos [?]: 2 [0], given: 7

Current Student
Joined: 04 Aug 2013
Posts: 30

Kudos [?]: 16 [4], given: 12

Concentration: Finance, Real Estate
GMAT 1: 740 Q47 V46
GPA: 3.23
WE: Consulting (Real Estate)
Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

18 Nov 2013, 18:45
4
KUDOS
1
This post was
BOOKMARKED
runningguy wrote:
Could someone also do this problem plugging numbers. I tried but it is not working.

I had trouble coming up with the above approach so i tried plugging numbers.

You are told John worked 10 hrs and Mary worked 8, and they are EACH paid x dollars for their work. I chose 80 for x since it's a multiple of
8 and 10. In this case, John is paid 8/hr and Mary is paid 10/hr. Since they have to be paid the same amount, Mary gives $1 to John (remember, y represents the amount of money she gives to John, so here y = 1). John now earns$9/hr or 9y.

Kudos [?]: 16 [4], given: 12

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7800

Kudos [?]: 18136 [6], given: 236

Location: Pune, India
Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

18 Nov 2013, 20:32
6
KUDOS
Expert's post
runningguy wrote:
Could someone also do this problem plugging numbers. I tried but it is not working.

Number plugging could work like this:

John worked on the job for 10 hours and Mary worked for 8 hours. They were both paid an equal amount but Mary gave John some of her amount so that they both get the same hourly wage. We can easily imagine this by assuming that they both got $9 each initially and Mary gave$1 to John so that Mary got $8 (@$1 per hr) and John got $10 (@$1 per hr).
So x could be $9 and y could be$1.
We need x in terms of y which is x = 9y
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Kudos [?]: 18136 [6], given: 236 Current Student Joined: 10 Nov 2013 Posts: 20 Kudos [?]: 16 [0], given: 130 Location: United States Concentration: Healthcare, Strategy WE: Information Technology (Health Care) Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 01 Dec 2013, 10:19 HCalum11 wrote: runningguy wrote: Could someone also do this problem plugging numbers. I tried but it is not working. I had trouble coming up with the above approach so i tried plugging numbers. You are told John worked 10 hrs and Mary worked 8, and they are EACH paid x dollars for their work. I chose 80 for x since it's a multiple of 8 and 10. In this case, John is paid 8/hr and Mary is paid 10/hr. Since they have to be paid the same amount, Mary gives$1 to John (remember, y represents the amount of money she gives to John, so here y = 1). John now earns $9/hr or 9y. Exactly!.. I picked up the same approach with 800$ provided to Mary and John.. It is easier to choose the multiple of rates when picking up a number instead of a just using a 100$approach.. Kudos [?]: 16 [0], given: 130 Manager Joined: 13 Jul 2013 Posts: 69 Kudos [?]: 14 [0], given: 21 GMAT 1: 570 Q46 V24 Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 29 Dec 2013, 18:44 I tried this but I am not getting the answer. Lets assume Both John and Mary got 8 and 8 advance. Mary gave john$2 as she worked 2 hour less.
So y=2.

Where am I going wrong?

Kudos [?]: 14 [0], given: 21

Math Expert
Joined: 02 Sep 2009
Posts: 42618

Kudos [?]: 135755 [1], given: 12708

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

30 Dec 2013, 00:15
1
KUDOS
Expert's post
theGame001 wrote:
I tried this but I am not getting the answer.

Lets assume Both John and Mary got 8 and 8 advance.
Mary gave john $2 as she worked 2 hour less. So y=2. Answer: a. Where am I going wrong? We are told that after Mary gave John y dollars they received the same hourly wage. Your example does not provide that. Try using$9 advance pay instead or check Karishma's post for number plugging here: john-and-mary-were-each-paid-x-dollars-in-advance-to-do-a-144782.html#p1294268 or algebraic approach here: john-and-mary-were-each-paid-x-dollars-in-advance-to-do-a-144782.html#p1161559

Hope this helps.
_________________

Kudos [?]: 135755 [1], given: 12708

Manager
Joined: 04 Oct 2013
Posts: 161

Kudos [?]: 126 [1], given: 55

Location: India
GMAT Date: 05-23-2015
GPA: 3.45
Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

31 Dec 2013, 07:58
1
KUDOS
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

John worked 10 hours and paid x dollars
Mary worked 8 hours and paid x dollars

John and Mary together worked: $$10 + 8 = 18 hours$$
John and Mary together paid :$$x + x = 2x$$

Hence, hourly wage or wage/hour $$= 2x/18$$ or $$x/9$$

As per hourly wage, john is paid less by an amount $$(x/9)*10 - x$$ Or, $$x/9$$
Or, Mary is paid more by an amount $$x - (x/9)*10$$ or $$x/9$$

Or, $$x/9$$ is the amount Mary gave John so that they would have received the same hourly wage.
Or, $$x/9 = y$$
Or, $$x = 9y$$

Kudos [?]: 126 [1], given: 55

Manager
Joined: 12 Jan 2013
Posts: 217

Kudos [?]: 83 [0], given: 47

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

10 Jan 2014, 03:35
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

I did NOT solve this question correctly but I still got to the correct answer because I knew that 9 needed to be included in the correct answer because of this:

Initially we are given x + x = Total Advance. Then, given that Mary gives John y USD of her payment, we have: 10(x + y) + 8(x - y) = Total Advance ----> 10x + 10y + 8x - 8y = TA ----> 18x + 2y = TA ----> 9x + y = TA.. There is no multiple of 9 in the answer other than E, thus I came to the correct answer even though I knew I hadn't done sufficient calculations to solve for the exact value of 9y.

Of course, this approach is very flawed because nothing out of 9x + y tells us that the answer should be 9y.. But given that more than 40% of everyone who did this question failed it, I find it quite obvious that the "correct" approach is not intuitive to a lot of us.

IMO, the GMAT is not a test where you're successful only if you know 100% of everything; a big portion of the test consists of making qualified guesses, otherwise many of us spend too much time trying to solve problems that obviously are over our heads (like this one, for me). With that in mind, I think this approach - seeing a possible pattern - is a weak but viable approach.

Last edited by aeglorre on 10 Jan 2014, 03:47, edited 2 times in total.

Kudos [?]: 83 [0], given: 47

Manager
Joined: 20 Dec 2013
Posts: 130

Kudos [?]: 114 [2], given: 1

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

10 Jan 2014, 03:45
2
KUDOS
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

Let us say that both got $40 for the job, x = 40 John --- 10 hours ----$ 40 ----- After paying ---- 40 + y
Mary --- 8 hours ------ $40 ----- After paying ----- 40 - y Now the rate is same: (40 + y)/10 = (40 - y)/8 160 + 4y = 200 - 5y 9y = 40 y = 40/9 By putting y = 40/9 we should get x = 40 which is answer option E. _________________ 76000 Subscribers, 7 million minutes of learning delivered and 5.6 million video views Perfect Scores http://perfectscores.org http://www.youtube.com/perfectscores Kudos [?]: 114 [2], given: 1 Senior Manager Joined: 15 Aug 2013 Posts: 298 Kudos [?]: 84 [0], given: 23 Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 28 Oct 2014, 17:46 VeritasPrepKarishma wrote: runningguy wrote: Could someone also do this problem plugging numbers. I tried but it is not working. Number plugging could work like this: John worked on the job for 10 hours and Mary worked for 8 hours. They were both paid an equal amount but Mary gave John some of her amount so that they both get the same hourly wage. We can easily imagine this by assuming that they both got$9 each initially and Mary gave $1 to John so that Mary got$8 (@$1 per hr) and John got$10 (@ $1 per hr). So x could be$9
and y could be $1. We need x in terms of y which is x = 9y Hi Karishma, I actually tried the number approach as well and did EXACTLY that, with those same exact numbers, but for some reason, didn't think that the answer was the right answer. Mary worked 8 hours. John worked 10 hours. Let's say they both earned 80 dollars, which would make: Mary's hourly wage:$10/hr
John's hourly wage: $8/hr To get the same wage, lets say 9, mary would earn$9/hr and John would earn 11/hr. But doing so, the total gets misaligned. Now, Mary's total wage will be (9/hr)(8hr) = $72 and John's will be (11$/hr)(10hr) = $110. Don't they need to earn the same TOTAL money? How can this work if they need to earn the same total? Thanks! Bunuel wrote: Walkabout wrote: John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance? (A) 4y (B) 5y (C) 6y (D) 8y (E) 9y The amount Mary has in the end is x-y dollars and she worked for 8 hours; The amount John has in the end is x+y dollars and he worked for 10 hours;; We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$. Answer: E. Bunuel, I can completely follow the logic below but I had no idea that we were solving for x. How did you come up with the concept, albeit correct, that we were solving for x? Thanks! Kudos [?]: 84 [0], given: 23 Intern Joined: 31 Aug 2014 Posts: 2 Kudos [?]: [0], given: 2 Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 24 Dec 2014, 07:58 Bunuel wrote: Walkabout wrote: John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance? (A) 4y (B) 5y (C) 6y (D) 8y (E) 9y The amount Mary has in the end is x-y dollars and she worked for 8 hours; The amount John has in the end is x+y dollars and he worked for 10 hours;; We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$. Answer: E. Hi Bunuel My doubt is that shouldn't the amount Mary and John have in the end also contains (Hourly wage * No. of hours)? I solved it like this : Total revenue of John= x +10(hourly wage)+y Similarly for Mary, it will be = x+8(hourly wage)-y Since, Mary gives y amount to John which corresponds to extra 2 hours worked by John and 2 less hours by Mary 2 * hourly wage = y or hourly wage = y/2 final equation to equate hourly wages (x+(10y/2)+ y)/10 = (x+(8y/2)-y)/8 (x+6y)/10 = (x+3y)/8 hence, x=9y Isn't this the right approach? Thanks Kudos [?]: [0], given: 2 Math Expert Joined: 02 Sep 2009 Posts: 42618 Kudos [?]: 135755 [0], given: 12708 Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 24 Dec 2014, 08:00 russ9 wrote: VeritasPrepKarishma wrote: runningguy wrote: Could someone also do this problem plugging numbers. I tried but it is not working. Number plugging could work like this: John worked on the job for 10 hours and Mary worked for 8 hours. They were both paid an equal amount but Mary gave John some of her amount so that they both get the same hourly wage. We can easily imagine this by assuming that they both got$9 each initially and Mary gave $1 to John so that Mary got$8 (@$1 per hr) and John got$10 (@ $1 per hr). So x could be$9
and y could be $1. We need x in terms of y which is x = 9y Hi Karishma, I actually tried the number approach as well and did EXACTLY that, with those same exact numbers, but for some reason, didn't think that the answer was the right answer. Mary worked 8 hours. John worked 10 hours. Let's say they both earned 80 dollars, which would make: Mary's hourly wage:$10/hr
John's hourly wage: $8/hr To get the same wage, lets say 9, mary would earn$9/hr and John would earn 11/hr. But doing so, the total gets misaligned. Now, Mary's total wage will be (9/hr)(8hr) = $72 and John's will be (11$/hr)(10hr) = $110. Don't they need to earn the same TOTAL money? How can this work if they need to earn the same total? Thanks! Bunuel wrote: Walkabout wrote: John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance? (A) 4y (B) 5y (C) 6y (D) 8y (E) 9y The amount Mary has in the end is x-y dollars and she worked for 8 hours; The amount John has in the end is x+y dollars and he worked for 10 hours;; We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$. Answer: E. Bunuel, I can completely follow the logic below but I had no idea that we were solving for x. How did you come up with the concept, albeit correct, that we were solving for x? Thanks! We are told that John was paid x dollars in advance. The question asks: what was the dollar amount, in terms of y, that John was paid in advance? So, it asks to find x (the dollar amount that John was paid in advance) in terms of y. Hope it's clear. _________________ Kudos [?]: 135755 [0], given: 12708 Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 7800 Kudos [?]: 18136 [1], given: 236 Location: Pune, India Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 25 Dec 2014, 19:19 1 This post received KUDOS Expert's post russ9 wrote: VeritasPrepKarishma wrote: runningguy wrote: Could someone also do this problem plugging numbers. I tried but it is not working. Number plugging could work like this: John worked on the job for 10 hours and Mary worked for 8 hours. They were both paid an equal amount but Mary gave John some of her amount so that they both get the same hourly wage. We can easily imagine this by assuming that they both got$9 each initially and Mary gave $1 to John so that Mary got$8 (@$1 per hr) and John got$10 (@ $1 per hr). So x could be$9
and y could be $1. We need x in terms of y which is x = 9y Hi Karishma, I actually tried the number approach as well and did EXACTLY that, with those same exact numbers, but for some reason, didn't think that the answer was the right answer. Mary worked 8 hours. John worked 10 hours. Let's say they both earned 80 dollars, which would make: Mary's hourly wage:$10/hr
John's hourly wage: $8/hr To get the same wage, lets say 9, mary would earn$9/hr and John would earn 11/hr. But doing so, the total gets misaligned. Now, Mary's total wage will be (9/hr)(8hr) = $72 and John's will be (11$/hr)(10hr) = $110. Don't they need to earn the same TOTAL money? How can this work if they need to earn the same total? Thanks! The numbers I have assumed are that Mary and John got a TOTAL of$9 each initially (same total wage received). Then Mary gave John $1 so that Mary got a total of$8 and John got a total of $10. They hourly wages are$1/hour (same for both). This gives x = $9 and y =$1.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Kudos [?]: 18136 [1], given: 236 Director Joined: 10 Mar 2013 Posts: 589 Kudos [?]: 494 [0], given: 200 Location: Germany Concentration: Finance, Entrepreneurship GMAT 1: 580 Q46 V24 GPA: 3.88 WE: Information Technology (Consulting) Re: John and Mary were each paid x dollars in advance to do a [#permalink] ### Show Tags 30 May 2015, 07:00 John and Mary worked together 18 Hours and received (let's say) 36$ --> Wage 2$/hour John received: 18$ and worked 10 hours
Mary received: 18$and worked 8 hours --> Mary should have received 8hours*2$ =16$, so Mary must give John 2$ (our Y)
We know that John received 18$in advance which is equal to 9y (9*2$)
_________________

When you’re up, your friends know who you are. When you’re down, you know who your friends are.

800Score ONLY QUANT CAT1 51, CAT2 50, CAT3 50
GMAT PREP 670
MGMAT CAT 630
KAPLAN CAT 660

Kudos [?]: 494 [0], given: 200

Intern
Joined: 18 Jul 2015
Posts: 43

Kudos [?]: 13 [0], given: 33

Location: Brazil
Concentration: General Management, Strategy
GMAT 1: 640 Q39 V38
GMAT 2: 700 Q47 V38
Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

16 Feb 2016, 13:38
Hourly wage = x/total time worked

John works for 10 hours
Mary works of 8 hours

Hourly wage of John = (x+y)/10
Hourly wage for Mary= (x-y)/8

Since both hourly wage must be the same,
(x+y)/10=(x-y)/8
18y=2x
9y=x

Kudos [?]: 13 [0], given: 33

Board of Directors
Joined: 17 Jul 2014
Posts: 2698

Kudos [?]: 451 [0], given: 208

Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

25 Mar 2016, 17:47
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

looks more like a 600 lvl question...
each pre-paid X $we know that (x-y)/8 - hourly rate for marry is equal to (x+y)/10 - hourly rate for john. and these two are equal cross multiply and get: 10x-10y=8x+8y 2x=18y x=9y we are asked how much john was pre-paid. he received x$. but x=9y

E

Kudos [?]: 451 [0], given: 208

Intern
Joined: 07 Feb 2012
Posts: 15

Kudos [?]: 1 [0], given: 1

Concentration: Strategy
GMAT 1: 720 Q48 V41
John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

27 Mar 2016, 22:03
Bunuel wrote:
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

The amount Mary has in the end is x-y dollars and she worked for 8 hours;
The amount John has in the end is x+y dollars and he worked for 10 hours;;

We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$.

Hi Bunuel,

Could you please let me know where I went wrong in my approach?

I assumed that that the advance amount given to each person was 40 $. (X=40). As John worked 10 hours and Mary worked 8 hours, John's hourly rate = 40/10=4$/hr
Mary's houry rate = 40/8=5/hr

For Mary to receive the same hourly rate as John (4$/hr), she would have had to earn only 4*8 = 32$

Hence the amount to be given to John = 40-32=8 (i.e y = 8 in this case)

In this case 40=5(8) i.e. x=5y (option B)

Kudos [?]: 1 [0], given: 1

Math Expert
Joined: 02 Sep 2009
Posts: 42618

Kudos [?]: 135755 [0], given: 12708

Re: John and Mary were each paid x dollars in advance to do a [#permalink]

### Show Tags

28 Mar 2016, 01:14
deliverance wrote:
Bunuel wrote:
John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours and Mary worked 2 hours less than John. If Mary gave John y dollars of her payment so that they would have received the same hourly wage, what was the dollar amount, in terms of y, that John was paid in advance?

(A) 4y
(B) 5y
(C) 6y
(D) 8y
(E) 9y

The amount Mary has in the end is x-y dollars and she worked for 8 hours;
The amount John has in the end is x+y dollars and he worked for 10 hours;;

We are told that in this case their hourly wage was the same: $$hourly \ wage=\frac{wage}{# \ of \ hours \ worked}=\frac{x-y}{8}=\frac{x+y}{10}$$, from $$\frac{x-y}{8}=\frac{x+y}{10}$$ we get that $$x=9y$$.

Hi Bunuel,

Could you please let me know where I went wrong in my approach?

I assumed that that the advance amount given to each person was 40 $. (X=40). As John worked 10 hours and Mary worked 8 hours, John's hourly rate = 40/10=4$/hr
Mary's houry rate = 40/8=5/hr

For Mary to receive the same hourly rate as John (4$/hr), she would have had to earn only 4*8 = 32$

Hence the amount to be given to John = 40-32=8 (i.e y = 8 in this case)

In this case 40=5(8) i.e. x=5y (option B)

The point is that when Mary gives John y dollars of her payment, Mary's hourly wage will decrease and John's hourly wage will increase. In your case Mary's hourly wage is $4 while John's hourly wage becomes 48/10=$4.8. As you can see the hourly wages are not equal.
_________________

Kudos [?]: 135755 [0], given: 12708

Re: John and Mary were each paid x dollars in advance to do a   [#permalink] 28 Mar 2016, 01:14

Go to page    1   2    Next  [ 24 posts ]

Display posts from previous: Sort by