M4maths Previous Puzzles

19 Nov 2015 Time and Work

Mukesh and Chandan can complete a task in 30 days when working together. After Mukesh and Chandan have been working together for 11 days, Chandan is called away and Mukesh, all by himself completes the task in the next 28 days. Had Mukesh been working alone, the number of days taken by him to complete the task would have been

OPtion

1) 379/9
2) 874/11
3) 520/11
4) 590/11
5) 859/9
6) 595/9
7) 444/9
8) 840/19
9) 533/9
10)None of these

Solution

(M+C)'s 11 days task = 11/30
Remaining work = 1 - 11/30 = 19/30
19/30 work is done by M in 28 days.
Whole work will be done by M in (28*30/19) = 840/19
Option 8)

Correct Option: 8 Best Solution (21)

BONAM SRINIVAS   9 years AGO

let mukesh=x, chandan=y
now x+y can complete work in 30 days. x+y one day work=1/30
given x+y worked for 11 days so,x+y 11 days work=11(1/30).
now remainini work=1-11/30 (since total work is one) i.e.,1-11/30=19/30.
this 19/30 work is done by mukesh in 28 days(given remaining work is done by mukesh)
19/30 work-------->28 days
1 work -------------->???
(1*28)/(19/30)=(28*30)/19=840/19=ans.

Like? Yes (5) | No (1)  

NAVEEN KUMAR   9 years AGO

workdone by mukesh&chandan in 11 days=11/30
hence , remaining work=1-11/30=19/30
A/Q..in 28 days mukesh complete the 19/30 part of work
hence,workdone of mukesh in 1 day=19/(28*30)=19/840
So,mukesh can complete the work in 840/19 days

Like? Yes (2) | No   

CHANDAN KUMAR   9 years AGO

m+c=30
m=28
toatal work=840
R(m+c)=840/30=28/day
work in 11 days by both=28x11=308
rem. work=840-308=532
rm=532/28=19/day
m alone=840/19

Like? Yes (2) | No   

MURUGESAN.P   9 years AGO

total number of units=30*11*28=9240 units.
both of them 1 day unit=9240/30=338 unit
11 days they work together,
so they complete=11*308=3388
remaining work=9240-3388= 5852 unit
Mukesh completes the remaining unit in 28 days,
so his one day unit is 5852/28=209 unit
he will complete the all the unit in( 9240/209) days
after simplification it will become 840/19 days
so,option 8:840/19 is correct

Like? Yes (1) | No   

MRITUNJAY   9 years AGO

total work done by both mukesh and Chandan=1/30
work in 11 days=11/30
remaining work=19/30
time taken by mukesh alone to complete work is=28*30/19=840/19

option 8

Like? Yes (1) | No   

Riteswari sahu   9 years AGO

1 day work of both = 1/30
11 day work of both = 11/30
remaining work = (1-11/30)= 19/30
mukesh completed it in 28 day = (19/30)*28= 840/19

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ramakrishna   9 years AGO

mukesh and chandana can do the work =30 days
in11 days they completed =11 th part of work
remaining work=19
19 th part of work completed in 28 days by mukesh
so mukesh can complete the work in 30*28/19=840/19

Like? Yes (1) | No   

SHUBHAM   9 years AGO

(1/X + 19/(30*28))=1/30
1/X=3/280,
(3/280+1/y=1/30),
y=840/19

Like? Yes (1) | No   

chetan   9 years AGO

(M+C)'s 11 days work =(1*11)/30=11/30.
Remaining work=1-(11/30)=19/30.
Whole work will be done in (30*28)/19=840/19.
So option 8 is correct.

Like? Yes (1) | No   

Jagadeesh   9 years AGO

M+C=30 days
1 day work (M+C)=1/30 days
11 days work both together=11/30
remaining work=1-11/30=19/30
19/30 days work done in 28 days
1 day work=28*30/19
11/30 day work=28*11/19
total work=28*11/19 +28
equals to 840/19

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Pooja Shaw   9 years AGO

Mukesh+Chandan can complete the work in 30 days
in 1 day Mukesh+chandan can complete 1/30 of the work
There fore,in 11 days Mukesh +chandan will complete 11/30 of the work
Remaining work=1-11/30=19/30
19/30 of the work is completed in 28 days by Mukesh
therefore the whole work will be completed in (28*(30/19))=840/19 days.
Thus correct option is 8)840/19

Like? Yes (1) | No   

aditya vasudeva   9 years AGO

one day work of mukesh and chandan combined = 1/30
Let one day work of mukesh = 1/m and one day work of chandan = 1/c
one day work of chandan = 1/30 - one day work of mukesh
11*(1/m+1/30-1/m) = 11/30
Remaining work = 1-11/30 = 19/30
This remaining work is done by Mukesh in 28 days ...
28 * 1/m = 19/30
solving above equation we get m = 840/19 Answer...

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Abhisheak Kumar Missu   9 years AGO

m+c in 1 day= 1/30
m+c in11 day= 11/30
remaining work=1-11/30=19/30
mukesh does 19/30 work in 28 days
so 1 work will done in 28*30/19

Like? Yes (1) | No   

sushma g   9 years AGO

mukesh +chandan can do a work in 30days=1/30
mukesh and chandan working together,hence amount of work done by both=11/30
amount of work done=1-11/30=19/30
remaining work is completed by mukesh in 28 days=19/30*28=19/840
days taken by mukesh alone to complete is 840/19

Like? Yes (1) | No   

Akshaya   9 years AGO

Mukesh + Chandan = 30 days

(M + C)'s one day work = 1/30
For 11 days they are working together,
(M+C)'s 11 days work = (1/30)*11 = 11/30
Remaining work = 1 - 11/30 = 19/30
Now, 19/30 work is done by Mukesh in 28 days.
Therefore, the entire work will be done by Mukesh in 28 * (30/19) days.
i.e. Mukesh will take 840/19 days to complete the entire work.

Like? Yes (1) | No   

Nandkishor jaiswal   9 years AGO

from the question
30(1/m+1/c)=1
or, 1/c=1/30-1/m ---------1
and 11(1/m+1/30-1/m)+28/m=1
or, 28/m=1-11/30
m=30*28/19=840/19

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Jaikumar Bhatia   9 years AGO

Let's
Mukesh=A
Chandan=B

(A+B)'s 11 day's work=[(1/30)*11]=11/30
Remaining work=[1-(11/30)]=19/30
now 19/30 work is done by A in 28 days
Then whole work will be done by A in [28*(30/19]=840/19

so ans is 840/19
Option is (8)

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Devendra Marghade   9 years AGO

1 day work of Mukesh & Chandan is 1/M & 1/C respectively, then, 1/M+1/C= 1/30 ---(i)
Also 11[(1/M)+(1/C)]+28/M=1 or 29/M +11/C=1 ---(ii)
Substituting 1/C=(1/30)-(1/M) in (ii), we get 28/M=19/30 or
1/M=19/840
So Mukesh working alone can complete the task in 840/19 days Option 8)

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V CHANDRA SHEKHAR   9 years AGO

(MUKESH+CHANDAN)'S11 DAYS WORK=(1/30)*11=11/30

REMAINING WORK=1-11/30=19/30

NOW 19/30 WORK IS DONE BY MUKESH IN 28 DAYS ,

THEREFORE ,THE WHOLE WORK WILL BE DONE BY
MUKESH IN (28*30)/19 DAYS =840/19 DAYS

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Saurabh Agrawal   9 years AGO

left work of 19 days done by mukesh in = 28 days
i.e. work of 1 day can be done by mukesh is =28/19 days
i.e. work of 30 days can be done by mukesh alone is =(28/19)*30=840/19

Like? Yes (1) | No   

Ankusj   9 years AGO

Let time taken by mukesh be x days and chandan be y days.
So, 1/x+1/y= 1/30
Now, 11*(1/x+1/y) +28/x=1
Solving this..x= 840/19

Like? Yes (1) | No