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?
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 2 of 7.
Raju said:
8 years ago
A, B, and C working togather can finish cerain piece of work in 40 days. If A and B work together then take 1/3 less time than that of C takes alone. If A andBC work together than they take 1/4 less time than that B takes alone. In how many days B and C working together will finish the work? Can anyone solve this?
Ashutosh said:
6 years ago
A and B together can complete a work in 30 day. They started together but after 6
days A left the work and the work is completed by B after 36 more days. A alone can complete
the entire work in how many days?
Please answer fast and answer is 90 btw ssc cpo question with answer that is 90.
days A left the work and the work is completed by B after 36 more days. A alone can complete
the entire work in how many days?
Please answer fast and answer is 90 btw ssc cpo question with answer that is 90.
Senchu Thomas said:
9 years ago
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.
ie, remaining work is 30 - 20 = 10.
10 work in 20 days.
So 1 work 2 days.
So 30 work in 30*20 = 60 days.
They worked together for 20 days and then B left.
After another 20 days, A finished the remaining work.
ie, remaining work is 30 - 20 = 10.
10 work in 20 days.
So 1 work 2 days.
So 30 work in 30*20 = 60 days.
Ancy said:
2 years ago
A+B' s can finish work = 30 days
if,
A+B work together = 20 days
Therefore, 30:20 =3:2 (3 is the total work & 2 is together work)
= 3-2 = 1 (1 is remaining A's work)
A's remaining work is 20 days
= 20 * 3 = 60 days.
if,
A+B work together = 20 days
Therefore, 30:20 =3:2 (3 is the total work & 2 is together work)
= 3-2 = 1 (1 is remaining A's work)
A's remaining work is 20 days
= 20 * 3 = 60 days.
(18)
Tarun said:
6 years ago
The work completed by A&B in one day is,
1/A + 1/B = 1/30 ---> (1)
(1/A + 1/B) * 20 + 1/A * 20 = 1 ---> (2)
Substitute the value of equation (1) in equation (2),
20/30 + 20/A = 1,
20/A = 10/30,
1/A = 1/60.
So, A alone can finish work in 60 days.
1/A + 1/B = 1/30 ---> (1)
(1/A + 1/B) * 20 + 1/A * 20 = 1 ---> (2)
Substitute the value of equation (1) in equation (2),
20/30 + 20/A = 1,
20/A = 10/30,
1/A = 1/60.
So, A alone can finish work in 60 days.
Harish said:
9 years ago
(A + B) does a piece of work in 30 days.
Therefore (A+B) = 1/30.
Then (A+B) does the same work together for 20 days, so it is taken as 1/20 days.
Remaining work = 1/30 - 1/20 = 1/60 days.
1/60 = 60 days.
The whole work will be done by A = 60 days.
Therefore (A+B) = 1/30.
Then (A+B) does the same work together for 20 days, so it is taken as 1/20 days.
Remaining work = 1/30 - 1/20 = 1/60 days.
1/60 = 60 days.
The whole work will be done by A = 60 days.
Abdul Khalique said:
9 years ago
Don't stress, if both can complete a work in 30 days, it'll take 60 days for alone A to complete the job.
Here 2X equals 2 person i.e. A&B.
If 2X = 30days, X = 30days ÷ 2, ie X = 60days.
It may be A or B.
Here 2X equals 2 person i.e. A&B.
If 2X = 30days, X = 30days ÷ 2, ie X = 60days.
It may be A or B.
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.
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.
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.
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.
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.
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