Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 13)
13.
A and B can together finish a work 30 days. They worked together for 20 days and then B left. After another 20 days, A finished the remaining work. In how many days A alone can finish the work?
40
50
54
60
Answer: Option
Explanation:

(A + B)'s 20 day's work = ( 1 x 20 ) = 2 .
30 3

Remaining work = ( 1 - 2 ) = 1 .
3 3

Now, 1 work is done by A in 20 days.
3

Therefore, the whole work will be done by A in (20 x 3) = 60 days.

Discussion:
63 comments Page 4 of 7.

Sinchana Shettar said:   5 years ago
Please, Explain this with LCM method.

Saloni panigrahi said:   5 years ago
E * t = w.

Since e is inverse of t so 20 becomes 1/20.
Now 1/20*t=1/3 since we have to find the time taken so,
T =20/1/3 HENCE T= 60 because in LHS it is multiplication so after coming to RHS it will divide.

Balaji rajendran said:   10 years ago
@Deepak yadav.

In this problem A can finish 10 days work in 20 days so if he left alone to do a 30 days work, he will take 60 days to finish the work.

Asha said:   1 decade ago
Hey @ankush

The question here is that in how many days A alone can do the entire work..

So its very simple 1/3 work done in 20 days, 2/3 work in 20*2=40 days and 3/3 (i.e. 1)= 20*3=60 days.

Srishailam said:   1 decade ago
Am not understanding this problem any body please help me.

How A work come 20 days. Explain ?

Dhruv said:   1 decade ago
How come 1/3 work is done in 20 days should the work in 20 days not be 2/3?

Avi said:   1 decade ago
A & B together works for 30 days
so, (A & B)'s 1 day work= 1/30
A&B worked for 20 days together
it is said after working together for 20 days b left
so, (A&B)'s work for 20 days together = (1/30)x20=2/3
remaining work that is to be done =1-2/3=1/3
1/3 work is done in 20 days
1 work i.e; complete work would be done in 20/(1/3)=20x3=60 days

Kulbhushan said:   1 decade ago
Hi, how we calculated that 1/3 work in 20 days?

Manikandan said:   1 decade ago
@kulbhushan

Already 20 days work finished by A and B.Remaining 10 days work done by A in 20 days. If A alone able to finish 30 days work in 60days.

Joel said:   1 decade ago
I have 145 days left to complete the construction project out of 442 louvers to install with 4 manpower. How many installed louver will they need to installed if they work for 8 hours a day and they can only 8.


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