GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Dec 2018, 02:48

### 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 December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
• ### 10 Keys to nail DS and CR questions

December 17, 2018

December 17, 2018

06:00 PM PST

07:00 PM PST

Join our live webinar and learn how to approach Data Sufficiency and Critical Reasoning problems, how to identify the best way to solve each question and what most people do wrong.
• ### R1 Admission Decisions: Estimated Decision Timelines and Chat Links for Major BSchools

December 17, 2018

December 17, 2018

10:00 PM PST

11:00 PM PST

From Dec 5th onward, American programs will start releasing R1 decisions. Chat Rooms: We have also assigned chat rooms for every school so that applicants can stay in touch and exchange information/update during decision period.

# A factory normally produces x units per working day. In a month with 2

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Moderator
Joined: 21 Jun 2014
Posts: 1101
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

27 Nov 2018, 08:05
2
4
00:00

Difficulty:

35% (medium)

Question Stats:

74% (01:42) correct 26% (02:25) wrong based on 70 sessions

### HideShow timer Statistics

A factory normally produces x units per working day. In a month with 22 working days, no units are produced in the first y working days because of a strike. How many units must be produced per day on each of the rest of the working days of the month in order to have an average of x units per working day for the entire month?

(A) $$11x$$

(B) $$22x$$

(C) $$\frac{22x}{y}$$

(D) $$\frac{22x}{22-y}$$

(E) $$\frac{22x}{22xy-y}$$

Project PS Butler : Question #44

Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS

_________________

---------------------------------------------------------------
Target - 720-740
Project PS Butler - https://gmatclub.com/forum/project-ps-butler-practice-everyday-280904.html
http://gmatclub.com/forum/information-on-new-gmat-esr-report-beta-221111.html
http://gmatclub.com/forum/list-of-one-year-full-time-mba-programs-222103.html

VP
Joined: 09 Mar 2016
Posts: 1242
A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

27 Nov 2018, 11:00
HKD1710 wrote:
A factory normally produces x units per working day. In a month with 22 working days, no units are produced in the first y working days because of a strike. How many units must be produced per day on each of the rest of the working days of the month in order to have an average of x units per working day for the entire month?

(A) $$11x$$

(B) $$22x$$

(C) $$\frac{22x}{y}$$

(D) $$\frac{22x}{22-y}$$

(E) $$\frac{22x}{22xy-y}$$

Project PS Butler : Question #44

Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS

say 10 units are produced each day

for whole month 220*10 = 220 units are produced

now if strike lasted for 11 working days

then 11x=220

x = 20

let x be number of units per day 10

let 22-y be number of days left after strike 11

SO JUST PLUG IN THOSE VALUES TO GET 20

clearly A, B, and E are out

Between C and D,

D is more logical i think

IMO: D

i wonder how would an algebraic solution look like GMATPrepNow and how would you choose between D and C using my method of testing values - both yield the same value
CEO
Joined: 11 Sep 2015
Posts: 3240
Re: A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

27 Nov 2018, 11:49
2
Top Contributor
HKD1710 wrote:
A factory normally produces x units per working day. In a month with 22 working days, no units are produced in the first y working days because of a strike. How many units must be produced per day on each of the rest of the working days of the month in order to have an average of x units per working day for the entire month?

(A) $$11x$$

(B) $$22x$$

(C) $$\frac{22x}{y}$$

(D) $$\frac{22x}{22-y}$$

(E) $$\frac{22x}{22xy-y}$$

In a month with 22 working days, no units are produced in the first y working days because of a strike.
Number of days in which units were produced = 22 - y
Let k = units produced each day in which units were produced
So, TOTAL number of units produced in the month = k(22 - y)

How many units must be produced per day on each of the rest of the working days of the month in order to have an average of x units per working day for the entire month?
We want: (total number of units produced)/(# of work days) = x
In other words, we want: k(22 - y)/22 = x

We must solve the above equation for k

Take: k(22 - y)/22 = x
Multiply both sides by 22 to get: k(22 - y) = 22x
Divide both sides by (22 - y) to get: k = 22x/(22 - y)

RELATED VIDEO FROM OUR COURSE

_________________

Test confidently with gmatprepnow.com

Manager
Joined: 02 Oct 2018
Posts: 59
Re: A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

28 Nov 2018, 06:08
dave13 wrote:
HKD1710 wrote:
A factory normally produces x units per working day. In a month with 22 working days, no units are produced in the first y working days because of a strike. How many units must be produced per day on each of the rest of the working days of the month in order to have an average of x units per working day for the entire month?

(A) $$11x$$

(B) $$22x$$

(C) $$\frac{22x}{y}$$

(D) $$\frac{22x}{22-y}$$

(E) $$\frac{22x}{22xy-y}$$

Project PS Butler : Question #44

Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS

say 10 units are produced each day

for whole month 220*10 = 220 units are produced

now if strike lasted for 11 working days

then 11x=220

x = 20

let x be number of units per day 10

let 22-y be number of days left after strike 11

SO JUST PLUG IN THOSE VALUES TO GET 20

clearly A, B, and E are out

Between C and D,

D is more logical i think

IMO: D

i wonder how would an algebraic solution look like GMATPrepNow and how would you choose between D and C using my method of testing values - both yield the same value

dave13

Below is my working. Could let me know where i made a mistake?

Total Units per Month = 22x.

No. of units lost due to strike of y days = xy.

No. of units to be produced in the remainder of the month= 22x+xy

No. of days left in the month after strike y = 22-y.

Hence, per day rate= 22x+xy/ 22-y.
Manager
Joined: 17 May 2015
Posts: 249
Re: A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

28 Nov 2018, 07:06
2
Hi,

Given:

A factory normally produces x units per working day. In a month with 22 working days, no. of units required to be produced = 22*x units.

No units are produced in the first y working days because of a strike. => No. of working days reduced to (22 - y) days.

Now, the factory has to produce 22x units in (22-y) days. Hence, new average $$= \frac{22x}{22 - y}$$.

DAVE:

This is very much possible that with a particular set of values more than one option might be true. In such cases, you have to recheck the answer with another set of values.

For example, now consider x = 10, and y = 2. => In 22-y = 20 days factory has to produce 220 units => average = 220/20 = 11 units/day.

(C) 22x/y => (22*10)/2 = 110 units. OUT

(D) 22x/(22-y) => (22*10)/20 = 11 units. Option (D) matches, hence right answer.

ParthSanghavi

Quote:
Below is my working. Could let me know where i made a mistake?

Total Units per Month = 22x.

No. of units lost due to strike of y days = xy.

No. of units to be produced in the remainder of the month= 22x+xy

No. of days left in the month after strike y = 22-y.

Hence, per day rate= 22x+xy/ 22-y

Total production is fixed. Total units in a month = 22x. Hence, no. of units to be produced in a month will also be 22x.

Alternate Solution:

Old average = x units days.

No. of units lost due to strike = x*y units. These x*y units have to be produced on the remaining 22-y days.

No. of remaining working days = 22-y days.

New average $$= x + \frac{xy}{22 - y} = \frac{x*(22 - y) + xy}{22 - y} = \frac{ 22x - xy + xy}{22 - y} = \frac{22x}{22 -y}$$.

Hope this helps.

Thanks.
Manager
Joined: 02 Oct 2018
Posts: 59
Re: A factory normally produces x units per working day. In a month with 2  [#permalink]

### Show Tags

28 Nov 2018, 08:18
1
ganand wrote:
Hi,

Given:

A factory normally produces x units per working day. In a month with 22 working days, no. of units required to be produced = 22*x units.

No units are produced in the first y working days because of a strike. => No. of working days reduced to (22 - y) days.

Now, the factory has to produce 22x units in (22-y) days. Hence, new average $$= \frac{22x}{22 - y}$$.

DAVE:

This is very much possible that with a particular set of values more than one option might be true. In such cases, you have to recheck the answer with another set of values.

For example, now consider x = 10, and y = 2. => In 22-y = 20 days factory has to produce 220 units => average = 220/20 = 11 units/day.

(C) 22x/y => (22*10)/2 = 110 units. OUT

(D) 22x/(22-y) => (22*10)/20 = 11 units. Option (D) matches, hence right answer.

ParthSanghavi

Quote:
Below is my working. Could let me know where i made a mistake?

Total Units per Month = 22x.

No. of units lost due to strike of y days = xy.

No. of units to be produced in the remainder of the month= 22x+xy

No. of days left in the month after strike y = 22-y.

Hence, per day rate= 22x+xy/ 22-y

Total production is fixed. Total units in a month = 22x. Hence, no. of units to be produced in a month will also be 22x.

Alternate Solution:

Old average = x units days.

No. of units lost due to strike = x*y units. These x*y units have to be produced on the remaining 22-y days.

No. of remaining working days = 22-y days.

New average $$= x + \frac{xy}{22 - y} = \frac{x*(22 - y) + xy}{22 - y} = \frac{ 22x - xy + xy}{22 - y} = \frac{22x}{22 -y}$$.

Hope this helps.

Thanks.

Understood where i went wrong. Thank you :D
Re: A factory normally produces x units per working day. In a month with 2 &nbs [#permalink] 28 Nov 2018, 08:18
Display posts from previous: Sort by

# A factory normally produces x units per working day. In a month with 2

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.