A can lay railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in:
Simply you can do cross multiplication
we get
(12+16)/12*16
after solving we get
7/48
Second method:
Find the lcm of denominators
that's of 12 and 16
It is 48,and multiply it with each fractions
i:e
we get
(3+4)/48
Aparna said:
(Sun, Jan 2, 2011 01:50:00 AM)
@gurjit
as per formula,
If A's 1 day's work = 1/n , then A can finish the work in n days.
here also same
c's one days work=5/48
hence he can complete whole work in 48/5 days,tats asked to us
and remember any fraction can also be written in
quotient*remainder/divisor format
when solved 48/5
quotient=9
remainder=3
divisor=5
hence,
9*3/5
Bharathi said:
(Thu, Jan 6, 2011 04:19:09 AM)
How should know A, B, C work is 1/4.
Geetha said:
(Thu, Jan 6, 2011 08:56:31 AM)
@Bharathi
In ques they have mentioned that
with the help of C they did the job in 4 days
thatsy A+B+C=1/4
Sowjanya said:
(Fri, Jan 14, 2011 09:21:28 AM)
Thanks geeta you solved my doubt.
Reema said:
(Sun, Jan 16, 2011 07:59:05 AM)
How did 5/48 come explain it?
Naresh Kumar said:
(Tue, Jan 18, 2011 03:22:48 AM)
Thanks Aparna and Geetha. You have solved my doubt also.
I am very poor in solving such types of question.
Shantanu said:
(Wed, Jan 19, 2011 03:29:09 AM)
Reema
look
A's 1 day's work = 1/16
because he took 16 days to complete the task
similarly
C's 1 day's work =5/48
so total no. of days will be 48/5
Uthappa.U.K said:
(Thu, Jan 20, 2011 11:49:49 AM)
1/4-7/48 cannot be equal to 5/48. Can anyone explain this to me?
=(48-28)/192 = 20/192 //ok........ now its divisible by 4
=5/48 // r u got it?
Neelam said:
(Wed, Feb 2, 2011 01:05:20 AM)
Thanks uthaap, I was confused about the cross multiplication. Now you explained in easy manner.
Dinesk said:
(Tue, Feb 8, 2011 02:45:15 AM)
Nice aparna.
Sathya said:
(Sat, Feb 19, 2011 05:07:58 AM)
@Shantanu.
Your explain is very short and very sweet.
Shalu said:
(Fri, Mar 11, 2011 05:40:25 AM)
@Aparna
Why you substracted 1/4 -7/48 why dont you add 1/4+7/48 ?
Sagar said:
(Sat, Mar 19, 2011 12:02:16 AM)
@SHALU
SUPPOSE A,B,C ARE HAVING 10 RUPIEES
WE KNOW DAT A=5 AND B=3 NW WE HAVE TO FIND C
THEN WE WILL ADD BOTH A AND B AND REMOVE FRM TOTAL HERE ALSO SAME WE HAD DONE
UNDERSTOOD
Nalini said:
(Sun, Mar 27, 2011 01:53:04 PM)
@reema
take lcm of 1/4 - 7/48
i..e
12-7/48
= 5/48:)
got it??
Mallik said:
(Sat, Apr 30, 2011 01:09:06 PM)
Reema explained clearly.
Nikita said:
(Wed, Jun 15, 2011 02:07:17 AM)
1/4= 1/12+1/16+1/c
1/4-7/48=1/c
c=9*3/5
1/c= c's one day work
Sunil said:
(Sun, Jul 17, 2011 12:48:37 PM)
Why 48/5 is written? please help me.
Sunaina said:
(Wed, Jul 20, 2011 08:52:50 PM)
Why we should take 16 and 12 as 1/16 and 1/12?
Karthick said:
(Fri, Jul 22, 2011 01:28:27 PM)
Why the fraction 5/48 is changed to 48/5?
Shimpi said:
(Thu, Jul 28, 2011 01:26:51 PM)
Please help me in 1/4-7/48.
Srikanth said:
(Fri, Aug 5, 2011 07:17:52 PM)
How 48/5 is written as 9*3/5 ?
Sowmya said:
(Fri, Aug 5, 2011 10:56:26 PM)
@Srikanth
9*3/5=(9*5)+3=48/5
Ravi said:
(Sat, Aug 6, 2011 02:01:41 PM)
Thanks uththapa. I get it.
Saquib Ali said:
(Fri, Aug 19, 2011 10:25:58 AM)
You can solve all these sums very fast...
a can do the work in 16 days
b can do the work in 12 days
c can do the work in x days
Calc LCM of 16, 12 and x = 48x
units of work in a day by a = 48x/16 = 3x units
units of work in a day by b = 48x/12 = 4x units
units of work in a day by a = 48x/16 = 48 units
Total units of work in a day = 3x + 4x + 48= 7x+48
Thus in 4 days = 4(7x+48)= 28x+192
If A's 1 day work = 1/n than the complete/whole work can be done in n*1 days.
It can be modify to above 1 day's work, e.g
if A's 5 days work = 1/25, than the complete/whole work = 5*25= 125.
Simran said:
(Mon, Oct 17, 2011 11:53:47 AM)
Thanks for the help.
Vasudevarao said:
(Thu, Nov 17, 2011 09:30:38 AM)
Thank you nikitha well s. C method thanku.
Swetha said:
(Sat, Nov 26, 2011 03:10:25 PM)
1/12+1/16
=4+3/48
=7/48
Chandrakant said:
(Wed, Dec 14, 2011 12:37:56 AM)
Wan we do it this way?
A=16days B=12days, and A+B+C=4 days
So 16+12+C = 4
i.e; 28-4 = c
Hence c = 24days
NOTE: Pls tell me if this method is correct, if not then why?
Indian said:
(Wed, Dec 21, 2011 01:13:04 PM)
@ Ovii
Thanks for explanation, Now I understood well.
Tiny said:
(Sun, Jan 15, 2012 12:27:14 PM)
@chandrakant.
Your method is totaly wrong. When c comes in right hand side it will become negative.
Udita said:
(Sat, Jan 21, 2012 12:07:20 AM)
@Saquib Ali.
Please explain the following step.
Units of work in a day by a = 48x/16 = 48 units.
Amrut said:
(Mon, Mar 19, 2012 12:17:40 PM)
C s one day work is 5/48. But how you came to 48/5, I mean C finish job in 48/5 days. Is there any formula for this result?
Anshu said:
(Sat, Mar 31, 2012 12:00:41 PM)
"A" can do the 1/16 of the work in a day.
"B" can do the 1/12 of the work in a day.
A + b + c = 1/4 of the work.
1/16 + 1/12 + c = 1/4.
3/48 + 4/ 48 + c = 1/4.
7/48 + c = 1/4.
C = 1/4 - 7/48 = 12-7/48 = 5/48.
C can do 5/48 of the work per day.
Therefore he can complete his work on 48/5 days = 9 3/5.
Rajasekar said:
(Wed, Apr 4, 2012 01:49:54 PM)
How 5/48 is written 48/5?
Suryakiran Varma said:
(Tue, May 8, 2012 09:29:58 AM)
Look,
A can do a work in 16 days,so his one day work will be=1/16
and also B's one day work will be =1/12;
in the same way A,B,C together do a work in 4 days,so thier one day work will be=1/4
C 's one day work will be=(A+B+C)'s one day work - (A+B)'s one day work
i.e..
=(1/4)-(1/16+1/12)
=(1/4)-(7/48)
=(5/48)
thus,C's one day work is = 5/48,
so,he can do the work in 48/5 days..i.e..9 3/5.
Hiren said:
(Fri, Jun 8, 2012 11:02:06 AM)
Why you write 48/5 from 5/48.
Amit.J said:
(Tue, Jun 19, 2012 11:04:51 AM)
A+B+C=4 day.
A=16 day.
B=12 day.
C=?
Formula..
A+B+C=A*B*C/AB+BC+CA
4=192C/192+28C
4(192+28C)=192C
768+112C=192C
768=192C-112C
768=80C
768/80=C
C=48/5 Ans.
Parthasarathy said:
(Wed, Jun 20, 2012 09:50:51 AM)
@HIREN.
If A can do some work in N days.
So A can do that same work in one day =1/N.
So the answer 5/48 obtained by (1/4) - (1/16+1/4) =5/48.
So you should consider this as only 48/5.
Pradeep said:
(Sat, Jun 23, 2012 02:27:29 PM)
Thank you aparna.
Kalai said:
(Thu, Aug 23, 2012 08:57:49 PM)
I can't understand how 5/48 becomes 48/5. Can you clarify for me.
Shiyamala said:
(Wed, Aug 29, 2012 02:42:46 PM)
A=1/16;
B=1/12;
A+B=[1/16+1/12]
=[16+12/192]{1/16*12/12=16/192;1/12*16/16=16/192)
=28/192
=7/48 {4*7=28; 48*4=192)
C-[A+B]=1/4-7/48 {1/4*12/12=12/48)
=12-7/48
=5/48
but c work alone.so,48/5=9*3/5
Ajay Jabalpur said:
(Sun, Oct 7, 2012 11:09:48 AM)
@Hiren.
If A's one day work = 1/n, then A can finish the work in n/1 days.
Similarly,
C's one day work is 5/48, then C can finish the work in 48/5 days.
Twinkle said:
(Sat, Jan 19, 2013 07:25:02 PM)
A+B+C=1/4.
[1/16]+[1/12]+C=[1/4].
C=0.1041.
THEREFORE, 1/0.1041=48/5.
i.e: 9*3/5.
Sudha said:
(Sat, Mar 9, 2013 07:08:14 PM)
At the end of explanation,
C's 1 day work is 5/48 I calculated up to to this but how it comes work in 48/5 days.
Because acc. to formula if A's 1 day work is 1/n' then A can finish work in n' days.
Means only it comes 48. I am just confuse. please explain me.
Srinivas said:
(Wed, Mar 27, 2013 06:38:35 PM)
If I go for another way as follows:
A B and C can do work in 4days.
A alone 16 days.
B alone 12 days.
C alone ?... Lets assume it as X.
Let me apply this formula
Work done by A B and C put together i.e 4= (16*12*X)/(16+12+X) //(A*B*C)/(A+B+C).
28+X=48X.
28=47X.
X=28/47.
According To you Answer is Wrong How is it. Please Reply me As soon As possible.
Sonu said:
(Sat, Mar 30, 2013 11:08:13 AM)
Why do we take fraction and add and subtract everything?
C's 1 day's work =
