Rajesh and Mohan working separately can do a piece of work in 9 days and 12 days respectively. If th

M4maths Previous Puzzles

25 Feb 2016 Time and work

Rajesh and Mohan working separately can do a piece of work in 9 days and 12 days respectively. If they work for a day alternately, Rajesh beginning, in how many days, the work will be completed?

OPtion

1) 21/2
2) 11/2
3) 21/4
4) 43/3
5) 31/3
6) 41/3
7) 32/3
8) 31/4
9) 41/4
10)33/4

Solution

(Rajesh+Mohan)'s 2 day's work = 1/9 + 1/12 = 7/36
Work done in 5 pair of days = (5*7/36) = 35/36
Remaining work = (1 - 35/36) = 1/36
On 11th days it is Rajesh's Turn
1/9 : 1/36 :: 1 : x
x = 1/36 * 1 * 9
= 1/4 days
Therefore
Total time taken 10 1/4 = 41/4 days

Correct Option: 9 Best Solution (24)

THUMMALA VINEESHA   8 years AGO

Rajesh's 1 days's work=1/9
Mohan's 1 days work=1/12
two days work of both=(1/9)+(1/12)=7/36
for 10 days =35/36
remaining work=1/36
on 11th day rajesh's turn=1/36*9=1/4
totally 10(1/4)days==10+(1/4)=41/4

Like? Yes (7) | No   

ABHINAV PUSHPAM   8 years AGO

(rajesh +mohan)'s 2 days work = (1/9+1/12)= 7/36
work done in 5 pairs of days = (5*7/36)
remaining work = 1-35/36= 1/36.
on 11th day , 1/9th work will be done rajesh in 1 day.
1/36 work will be done by him in (9*1/36)= 1/4
so total time taken = 10+1/4= 41/4

option 9)

Like? Yes (3) | No   

MRITUNJAY   8 years AGO

Rajesh mohan.
9. 12
36
4. 3
4+3. in 2 days
7*5 =35 rasgulla in 5*2=10 days
remaining 1 rasgulla in 1/4
so total time is 10+1/4=41/4days
option 9

Like? Yes (1) | No   

sanjeet kumar   8 years AGO

Rajesh 1 day's work =1/9
Mohan 1 day's work = 1/12
Working together their's 1 day's work = 7/36
Therefore in 2 days work completed = 7/36;
so in 10 days work completed = 35/36;
Remaining work 1/36 is done by Rajesh in 1/4 days.
So total days taken = 10+1/4= 41/4

Like? Yes (1) | No   

mcamanjeet   8 years AGO

rajesh works =1/9 per day
mohan works =1/12 per day
sum of work in 2 days = 1/9+1/12=7/36
7*5/36 work in 10 days , 1/36 work is remaning
rajesh complete 1/9 in 1 day
then 1 in 9 days
and 1/36 in 9*1/36=1/4 days
finally in 10+1/4=41/4 days rajesh will complete the work .

Like? Yes (2) | No (1)  

UMANG RASTOGI   8 years AGO

let the seq. be RMRMRMRMRM
so 5/9 + 5/12 = 35/36 + x/9 = 1

x=.25
so 10.25 = "41/4" ANS.

Like? Yes (1) | No   

raja   8 years AGO

Rajesh 1 day-----> 1/9 th work
Mohan 1 day-----> 1/12 th work

Rajesh 1 day work + Mohan 1 day work -----> 1/9 + 1/12 =7/36 th of work

Thus in 2 days work done = 7/36 th of work

Rajesh + Mohan in 10 days ------> 35/36 th of work

Remaining work=1/36

rajesh does this in 1/4 day.

Total no. of days= 10+1/4
= 41/4

Like? Yes (1) | No   

Rakesh Kumar Kohli   8 years AGO

Work done by Rajesh in 1 day = 1/9
Work done by Mohan in 1 day = 1/12
as they work for a day alternatively so work done in 2 days by them = 1/9 + 1/12 = 7/36
In 10 days they will work = (7/36 )* 5 = 35/36
On 11th day it will be turn of Rajesh who will do the remaining 1/36 work in 1/4 days.
So the total time taken to finish work is 10 + 1/4 = 41/4 days

Like? Yes (1) | No   

Anee   8 years AGO

total units of work that needs to be completed is 36 units.
In 1 day A can complete 4 units of work & B can complete 3 units of work
If they work alternatively then they will complete the work in 10 1/4 days =41/4 days

Like? Yes | No   

himanshu   8 years AGO

leet total work to be done=36
effieiency of rajesh for one day=4
efficiency of mohan=3
their two day work=7
in 10 days work to be done=35
nw rajesh will take 1/4 time more
so answer is 41/4

Like? Yes | No   

aman aditya   8 years AGO

let total work is 36 unit (LCM of 9,12)
rejesh does in one day =36/9= 4 unit
mohan does in one day = 36/12 = 3 unit
in alternate days they do (4+3) unit in 2 days
So in 10 days 35 unit is done and final day it is rajesh turn so he does it in 1/4 days.
hence 10 + 1/4 =41/4

Like? Yes | No   

Devendra Marghade   8 years AGO

2 days work of Rajesh & Mohan= (1/9) + (1/12)=7/36
So upto 10 days work completed=5*7/36=35/36
Remaining work=1/36, which will be completed by Rajesh in (1/36)/(1/9)=1/4 days
So work will be completed in 10+(1/4)=41/4 days
Option 9)

Like? Yes | No   

Amit   8 years AGO

5/9+5/12=105/108
remaining work=3/108
now rajesh turn of work so
n/9=3/108
i.e. n=1/4
total days
2*5+1/4
41/4

Like? Yes | No   

Akshat Sood   8 years AGO

Let unit of work be 360 units
Work done by Rajesh in 1 Day=40units
Work done by Mohan in 1 Day=30units
Working alternately
5(40)+5(30)+1/4(40)=360 units
hence no. of days=10+1/4=41/4days

Like? Yes | No   

Mukund Manohar   8 years AGO

Number of days taken by Rajesh and Mohan to complete the work is 36/7 days =5+(1/7) days
They worked for a day alternately,so work will go till 5*2=10 days
and on the 11th day,Rajesh will work.So.the work will be completed in 10+(9/36) =10+(1/4)=41/4 days

Like? Yes | No   

ashok ubbathoti   8 years AGO

both rajesh and mohan can do in 7/36
if they work in alternative days for two days their work is 7/36
after 10 days their work is 35/36
remaining work is 1/36
it have to be done by rajesh
so 1/36 is rajesh's 1/4th of the day
so total days is 10+1/4
41/4

Like? Yes | No   

Sagar Kumar Subudhi   8 years AGO

in 10 days both will complete 0.9722 of work. On 11th day rajesh will be working and he will complete rest of work i.e. 0.0277778 of work in approx 6 hours. So 10.25 days

Like? Yes | No   

harsh dhir   8 years AGO

(1/9)+(1/12)=7/36
work is done in two days.
35/36 work will be done in 10 days.so remaining 1/36 work will be done by rajesh in 1/36*9=1/4 days.
so tatal days=10+1/4=41/4.

Like? Yes | No   

MAMTA KUMARI   8 years AGO

RAJESH+MOHAN 2 DAYS WORK=(1/9+1/12)=7/36
5 DAYS=5*7/36=35/36
REMG WRK (1-35/36)=1/36)
9*1/36=1/4 DAYS
=(10+1/4)=41/4

Like? Yes | No   

karthiga   8 years AGO

LCM of 9 & 12 is 36;
Rajesh one day work is 36/9=4;
Mohan one day work is 36/12=3;
they are working alternately,
In 10 days 35 part is completed;
next day start by Rajesh; He do 1/4th day;
so overall 10(1/4)days = 41/4 answer;

Like? Yes | No   

Akshat Mokashi   8 years AGO

Work done by both in a pair=7/36
now work done in 5 pair=(5*7/36)=35/36
Remaining work=1/36
A will take 9*1/36=1/4 days to complete this.
Total days req =10+1/4=41/4

Like? Yes | No   

purimitla venkatrao   8 years AGO

Daily they do 12 ,9 parts each other
12 ,9,12,9,12,9,12,9,12,9,3/12
10*1/4

Like? Yes | No   

alka patel   8 years AGO

both will take individually time 5.25 and 5 so total time is 10.25 ie. 41/4

Like? Yes | No   

Akshay Nivrutti Raskar   8 years AGO

(Rajesh's and Mohan's ) 2 day's work= 1/9 +1/12 = 7/36
Multiply 7/36 by number such that it isless than 1
therefore 5 * 7/36 =35/36
rajesh and mohan work for 5 days each to complete 35/36
Remaining work = 1/36
Rajesh will do remainming work in 9*1/36 = 1/4 days
Total days = 5 + 5 + 1/4 = 41/4

Like? Yes | No