It is currently 19 Nov 2017, 07:21

### 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

# Ferman can do a job in 6 days and Kelly can do the same job

Author Message
TAGS:

### Hide Tags

Intern
Joined: 09 Jul 2013
Posts: 10

Kudos [?]: 58 [5], given: 13

Concentration: Human Resources, Entrepreneurship
Schools: ISB '14
Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

06 Sep 2013, 11:13
5
KUDOS
12
This post was
BOOKMARKED
00:00

Difficulty:

35% (medium)

Question Stats:

74% (02:03) correct 26% (02:35) wrong based on 236 sessions

### HideShow timer Statistics

Ferman can do a job in 6 days and Kelly can do the same job in 8 days. They both undertake the job for $640. With the help of Mary, they finished it in 3 days. How much was paid to Mary? A.$75
B. $80 C.$85
D. $100 E.$120
[Reveal] Spoiler: OA

Kudos [?]: 58 [5], given: 13

Intern
Joined: 14 Aug 2013
Posts: 35

Kudos [?]: 93 [3], given: 4

Location: United States
Concentration: Finance, Strategy
GMAT Date: 10-31-2013
GPA: 3.2
WE: Consulting (Consumer Electronics)
Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

06 Sep 2013, 11:44
3
KUDOS
Ferman takes 6 days to complete the work, so he does 1/6th of the work in one day
similarly kelly does 1/8th of the work in one day.
Given they worked for 3 days=> 3(1/6+1/8)=7/8th of the work is done by Ferman and Kelly in 3 days
Remaining 1/8th of the work is done with the help of Mary.
So Mary share is proportional the amount of work done=> 1/8th of 640=80$Kudos [?]: 93 [3], given: 4 Verbal Forum Moderator Joined: 10 Oct 2012 Posts: 627 Kudos [?]: 1387 [1], given: 136 Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink] ### Show Tags 06 Sep 2013, 11:47 1 This post received KUDOS 1 This post was BOOKMARKED aparnaharish wrote: Ferman can do a job in 6 days and Kelly can do the same job in 8 days. They both undertake the job for$640. With the help of Mary, they finished it in 3 days. How much was paid to Mary?

A. $75 B.$80
C. $85 D.$100
E. $120 Rate of doing work for Ferman =$$\frac{1}{6}$$ and for Kelly =$$\frac{1}{8}$$. Also, as $$Time*Rate = Work$$, we have $$3*[\frac{1}{6}+\frac{1}{8}+r_{Mary}] = 1$$unit of work Thus,$$r_{Mary} = \frac{1}{3}-(\frac{1}{6}+\frac{1}{8})$$ $$\to r_{Mary} = \frac{1}{24}$$ Thus, work done by Mary in 3 days : $$3* \frac{1}{24}$$ = $$\frac{1}{8}$$ units of work, and as the payment is directly proportional to the work done, the payment for her =$$\frac{640}{8}$$= 80$

B.
_________________

Kudos [?]: 1387 [1], given: 136

Manager
Joined: 26 Feb 2013
Posts: 170

Kudos [?]: 52 [0], given: 25

Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

25 Sep 2013, 06:21
mau5 wrote:
aparnaharish wrote:
Ferman can do a job in 6 days and Kelly can do the same job in 8 days. They both undertake the job for $640. With the help of Mary, they finished it in 3 days. How much was paid to Mary? A.$75
B. $80 C.$85
D. $100 E.$120

Rate of doing work for Ferman =$$\frac{1}{6}$$ and for Kelly =$$\frac{1}{8}$$. Also, as $$Time*Rate = Work$$,

we have $$3*[\frac{1}{6}+\frac{1}{8}+r_{Mary}] = 1$$unit of work

Thus,$$r_{Mary} = \frac{1}{3}-(\frac{1}{6}+\frac{1}{8})$$ $$\to r_{Mary} = \frac{1}{24}$$

Thus, work done by Mary in 3 days : $$3* \frac{1}{24}$$ = $$\frac{1}{8}$$ units of work, and as the payment is directly proportional to the work done, the payment for her =$$\frac{640}{8}$$= 80$B. Why isn't Mary's rate 1/x ? as in 1 work per x days Kudos [?]: 52 [0], given: 25 Manager Joined: 23 May 2013 Posts: 122 Kudos [?]: 68 [0], given: 110 Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink] ### Show Tags 08 Nov 2013, 06:07 Skag55 wrote: Ferman can do a job in 6 days and Kelly can do the same job in 8 days. They both undertake the job for$640. With the help of Mary, they finished it in 3 days. How much was paid to Mary?

Why isn't Mary's rate 1/x ? as in 1 work per x days

you can take it as 1/x too. then work done in 1 day will be

1/6+1/8+1/x = 1/3
1/x = 1/24
so Mary does 1/24 work in 1 day. Hence in 3 days she does 3/24 = 1/8 of work.
_________________

“Confidence comes not from always being right but from not fearing to be wrong.”

Kudos [?]: 68 [0], given: 110

Non-Human User
Joined: 09 Sep 2013
Posts: 15689

Kudos [?]: 282 [0], given: 0

Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

06 Dec 2014, 13:38
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 282 [0], given: 0

Non-Human User
Joined: 09 Sep 2013
Posts: 15689

Kudos [?]: 282 [0], given: 0

Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

23 Dec 2015, 00:14
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 282 [0], given: 0

Non-Human User
Joined: 09 Sep 2013
Posts: 15689

Kudos [?]: 282 [0], given: 0

Re: Ferman can do a job in 6 days and Kelly can do the same job [#permalink]

### Show Tags

23 Dec 2016, 07:32
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 282 [0], given: 0

Re: Ferman can do a job in 6 days and Kelly can do the same job   [#permalink] 23 Dec 2016, 07:32
Display posts from previous: Sort by