Aptitude - Time and Work - Discussion

Please explain the remaining work.

Mitra please explain clearly.

Well done harsha.

Harsha realy well done.

Take it this way
1/5 work x does in 4 days
Remaining 4/5 is to be found
X+y does 1/20+1/12 in 1 day
Therefore x+y=2/15 w/d
Therefore 4/5 w = 2/15(w/d)/4/5(w)
We get 1/6(1/d)
Therefore 6 days
Therefore total wrk in 10 days

How 6+4?y should we add. Please help.

Well a simple logic

1day work x =1/20
y=1/12
x first start and works upto 4 days=4*1/20
then both x and y works upto some day to completework=a(1/20+1/12)
add (4*1/20)+a(1/20+1/12)=1
we will get the days where both x and y worked=a=6

So total days to complete work =4+6=10.

x can do a work in 20 days
y can do a work in 12 days
To find total work ,take LCM of 20 and 12 i.e 60
Therefore Total work =60
x's 1 day capacity =60/20 =3
Y's 1 day capacity =60/12 =5

Since x alone did work for 4 days,
4*3=12 ,
12 work done in 4 days
there fore remaining work = 60-12 =48
Remaining work was completed by both
remaining work / (x's per day capacity +y's per day capacity)=48/6= 6
therefore remaining work was completed in 6 days
Total work was completed in 4 + 6 = 10 days.

I hope this is useful...

1day per x work as = 1/20 && y= 1/12..

x do work 4days ..then 4*1/20=1/5 then remaining work= 1-1/5=4/5

Remaining work's done by y i.e. 1work ---> 12
4/5 ------> x
x=4/5 * 12 = 48/5 = 9.6day nearly = 10days..

It's good method to understand GUYS..!

6+4 =10
Is here 4 takes from the question? " X started the work alone and then after 4 days"