Saturday, December 14, 2019
07:43 AM (GMT +5)

Go Back   CSS Forums > CSS Compulsory Subjects > General Science & Ability > General Ability

General Ability Quantitative Ability/Reasoning ; Logical Reasoning ; Analytical Reasoning/Ability ; Mental Abilities

Reply Share Thread: Submit Thread to Facebook Facebook     Submit Thread to Twitter Twitter     Submit Thread to Google+ Google+    
 
LinkBack Thread Tools Search this Thread
  #1  
Old Tuesday, September 15, 2015
RMKamran's Avatar
Senior Member
 
Join Date: Dec 2011
Posts: 534
Thanks: 721
Thanked 386 Times in 238 Posts
RMKamran will become famous soon enough
Post Kindly solve this work question

Aoa,

Kindly solve this question. In this question, two different people are doing the same work, and this is confusing me in its solution

If 3 men or 6 boys can do a work in 20 days, then 6 men and 8 boys shall take:

A. 6 days.
B. 8 days.
C. 9 days.
D. 20 days.

P.S: Quick and detailed reply would be highly appreciated. Thanks in anticipation.

Regards.
__________________
Nasru minal'lahi wa fat'hun qareeb
Reply With Quote
  #2  
Old Tuesday, September 15, 2015
Mashaaal's Avatar
44th CTP (IRS)
CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: CE 2015 - Merit 162
 
Join Date: Jul 2014
Location: the snow angel expanse
Posts: 200
Thanks: 108
Thanked 195 Times in 98 Posts
Mashaaal is on a distinguished road
Default

my answer is 7.5 (approx 8 because 8 is not in the options)
the number of men and boys is increasing so they will be doing the work in less days, therefore men and boys are at inverse with days (so it is indirect proportion)

having a test tomorrow?
__________________
Striving for success without hard work is like trying to harvest where you never planted.

Last edited by Man Jaanbazam; Tuesday, September 15, 2015 at 01:20 AM. Reason: merge chain posts
Reply With Quote
  #3  
Old Tuesday, September 15, 2015
Member
 
Join Date: Aug 2015
Posts: 61
Thanks: 52
Thanked 17 Times in 14 Posts
FAHEEM ULLAH KHAN MAHSUD is on a distinguished road
Lightbulb Solution

Ans: Given, work can be done by:
3*20 = 60 man-days
or
6*20 = 120 boy-days
therefore
60 md = 120 b.d

divide by 60
md = 2bd
:
how many days will 6 men and 8 boys take to do the same work?
let d = no. days to accomplish this in terms of man-days
we know that 8bd = 4 md; therefore
6d + 4d = 60
10d = 60
d = 6 days for 6 men and 8 boys to do the job
__________________
"The sound of laughter has always seemed to me the most civilized music in the universe."
Reply With Quote
  #4  
Old Tuesday, September 15, 2015
RMKamran's Avatar
Senior Member
 
Join Date: Dec 2011
Posts: 534
Thanks: 721
Thanked 386 Times in 238 Posts
RMKamran will become famous soon enough
Exclamation

Quote:
Originally Posted by Mashaaal View Post
my answer is 7.5 (approx 8 because 8 is not in the options)
the number of men and boys is increasing so they will be doing the work in less days, therefore men and boys are at inverse with days (so it is indirect proportion)
Yup, I have a test tomorrow. I have done with the other part of mathematics but stuck in this weird question

8 is among the options. Btw, I know that it's indirect proportion but it's really confusing and I think this question is solved by a linear equation. Let's see if somebody else knows it.

Quote:
Originally Posted by FAHEEM ULLAH KHAN MAHSUD View Post
Ans: Given, work can be done by:
3*20 = 60 man-days
or
6*20 = 120 boy-days
therefore
60 md = 120 b.d

divide by 60
md = 2bd
:
how many days will 6 men and 8 boys take to do the same work?
let d = no. days to accomplish this in terms of man-days
we know that 8bd = 4 md; therefore
6d + 4d = 60
10d = 60
d = 6 days for 6 men and 8 boys to do the job
Jazak'ALLAH khairan.

Thanks a bunch bro but I didn't understand the 2nd part of your solution. Could you please throw some light on this: we know that 8bd = 4 md; therefore
6d + 4d = 60
10d = 60
d = 6 days for 6 men and 8 boys to do the job

How did you get 4md and where is 8bd after that step ?
__________________
Nasru minal'lahi wa fat'hun qareeb

Last edited by Man Jaanbazam; Tuesday, September 15, 2015 at 01:22 AM. Reason: merge chain posts
Reply With Quote
  #5  
Old Tuesday, September 15, 2015
Mashaaal's Avatar
44th CTP (IRS)
CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: CE 2015 - Merit 162
 
Join Date: Jul 2014
Location: the snow angel expanse
Posts: 200
Thanks: 108
Thanked 195 Times in 98 Posts
Mashaaal is on a distinguished road
Default

oh. it is boys or men,,, and i am taking it as boys and men, sorry,,
but yes you have written it both ways,, once you have written or' and then and'???? confused
__________________
Striving for success without hard work is like trying to harvest where you never planted.
Reply With Quote
  #6  
Old Tuesday, September 15, 2015
RMKamran's Avatar
Senior Member
 
Join Date: Dec 2011
Posts: 534
Thanks: 721
Thanked 386 Times in 238 Posts
RMKamran will become famous soon enough
Post

@Mishal

Mam, I have attempted by your method and it gives 7.5 that somehow makes '8' the right answer. But, still I am not satisfied and I think Faheem's method and answer is right.

@Faheem

Kindly reply. It's getting late.
__________________
Nasru minal'lahi wa fat'hun qareeb
Reply With Quote
  #7  
Old Tuesday, September 15, 2015
Senior Member
 
Join Date: Jun 2014
Location: Pakistan
Posts: 1,044
Thanks: 21
Thanked 418 Times in 329 Posts
Z Ali S is on a distinguished road
Default

Quote:
Originally Posted by RMKamran View Post
Aoa,

Kindly solve this question. In this question, two different people are doing the same work, and this is confusing me in its solution

If 3 men or 6 boys can do a work in 20 days, then 6 men and 8 boys shall take:

A. 6 days.
B. 8 days.
C. 9 days.
D. 20 days.

P.S: Quick and detailed reply would be highly appreciated. Thanks in anticipation.

Regards.
Quote:
Originally Posted by Mashaaal View Post
my answer is 7.5 (approx 8 because 8 is not in the options)
the number of men and boys is increasing so they will be doing the work in less days, therefore men and boys are at inverse with days (so it is indirect proportion)

having a test tomorrow?
3 men = 6 boys
Then, 1 boy = 3/6 men = 1/2 men
8 boys = 1/2 8 men = 4 men
Then, 6 men + 8 boys = 6 + 4 men = 10 men
work done = 3 men 20days
That is, 3 20 = 10 (required days)
3 2 = 1 (required days)
so (required days) =6.
Reply With Quote
  #8  
Old Tuesday, September 15, 2015
RMKamran's Avatar
Senior Member
 
Join Date: Dec 2011
Posts: 534
Thanks: 721
Thanked 386 Times in 238 Posts
RMKamran will become famous soon enough
Default

Quote:
Originally Posted by Z Ali S View Post
3 men = 6 boys
Then, 1 boy = 3/6 men = 1/2 men
8 boys = 1/2 8 men = 4 men
Then, 6 men + 8 boys = 6 + 4 men = 10 men
work done = 3 men 20days
That is, 3 20 = 10 (required days)
3 2 = 1 (required days)
so (required days) =6.


can you please express your solution in words ? I didn't understand it.
__________________
Nasru minal'lahi wa fat'hun qareeb
Reply With Quote
  #9  
Old Tuesday, September 15, 2015
exclusively's Avatar
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason:
 
Join Date: Jul 2013
Posts: 1,880
Thanks: 1,595
Thanked 1,286 Times in 782 Posts
exclusively has a spectacular aura aboutexclusively has a spectacular aura aboutexclusively has a spectacular aura about
Default

Pipe A can fill a tank in 3minutes, whereas b can fill it in 4minites. How long would it take both pipes working together to fill it?

What is logic of inverse in ans? can one one plz explain it?

Thanks in anticipation
Reply With Quote
  #10  
Old Tuesday, September 15, 2015
Adil Ashfaq's Avatar
Junior Member
 
Join Date: Apr 2013
Location: Lahore
Posts: 21
Thanks: 1
Thanked 15 Times in 10 Posts
Adil Ashfaq is on a distinguished road
Default

Quote:
Originally Posted by RMKamran View Post
Aoa,

Kindly solve this question. In this question, two different people are doing the same work, and this is confusing me in its solution

If 3 men or 6 boys can do a work in 20 days, then 6 men and 8 boys shall take:

A. 6 days.
B. 8 days.
C. 9 days.
D. 20 days.

P.S: Quick and detailed reply would be highly appreciated. Thanks in anticipation.

Regards.
1 Man = 2 Boys

Total Boy-days required to complete the task = 6 boys x 20 days = 120 Boy-days
120 days are required by one boy to complete the task.

Now come to the 'then' part.

because
6 men = 12 boys

therefore,

6 men + 8 boys = 12 boys + 8 boys = 20 boys

Now days required to complete the task = 120 boy-days /20 boys = 6 days


120 days are required by one boy to complete the task so the days required by 20 boys will be 120/20 = 6 days.

You can also solve by pursuing with the men instead of boys, i.e. 1 man = 2 boys.
__________________
Watu Izzu Man Tasha, Watu Zillu Man Tasha.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Psychology, By David G. Myers, 6th Edition sarfrazmayo Psychology 24 Sunday, July 20, 2014 04:47 PM
Popular idioms HASEEB ANSARI Grammar-Section 0 Tuesday, February 12, 2013 12:15 PM
Need help: Constitution's questions rqabutt Constitutional Law 11 Monday, February 07, 2011 11:06 PM


CSS Forum on Facebook Follow CSS Forum on Twitter

Disclaimer: All messages made available as part of this discussion group (including any bulletin boards and chat rooms) and any opinions, advice, statements or other information contained in any messages posted or transmitted by any third party are the responsibility of the author of that message and not of CSSForum.com.pk (unless CSSForum.com.pk is specifically identified as the author of the message). The fact that a particular message is posted on or transmitted using this web site does not mean that CSSForum has endorsed that message in any way or verified the accuracy, completeness or usefulness of any message. We encourage visitors to the forum to report any objectionable message in site feedback. This forum is not monitored 24/7.

Sponsors: ArgusVision   vBulletin, Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.