Aptitude - Time and Work - Discussion
Discussion Forum : Time and Work - General Questions (Q.No. 4)
4.
A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in:
Answer: Option
Explanation:
Ratio of times taken by A and B = 1 : 3.
The time difference is (3 - 1) 2 days while B take 3 days and A takes 1 day.
If difference of time is 2 days, B takes 3 days.
| If difference of time is 60 days, B takes |  |
3 | x 60 |  |
= 90 days. |
| 2 |
So, A takes 30 days to do the work.
| A's 1 day's work = | 1 |
| 30 |
| B's 1 day's work = | 1 |
| 90 |
| (A + B)'s 1 day's work = | |
1 | + | 1 | |
= | 4 | = | 2 |
| 30 | 90 | 90 | 45 |
 A and B together can do the work in |
45 | = 22 | 1 | days. |
| 2 | 2 |
Discussion:
281 comments Page 10 of 29.
Dusu opo said:
8 years ago
Why 60 days? Please explain.
Vishal said:
8 years ago
I have better solution.
A:B-3:1(rate).
A:B-1:3(days).
Diff of 2 between ratio of days which is equivalent to 60 and 2*30=60.
Hence 30 will be multiplied to 1 and 3.
And we get 30 and 90.
Together days taken= 30 * 90/30 + 90 = 22 1/2.
A:B-3:1(rate).
A:B-1:3(days).
Diff of 2 between ratio of days which is equivalent to 60 and 2*30=60.
Hence 30 will be multiplied to 1 and 3.
And we get 30 and 90.
Together days taken= 30 * 90/30 + 90 = 22 1/2.
Rizwan said:
8 years ago
From where does this 4/90 comes? How 4?
Nik said:
8 years ago
How 4/90 comes?
Pramod nepal said:
8 years ago
Let see @Shaman.
A finish work in x day and B can 5x day. Then we can do A+B= 1/x +1/5x.
We have A+B = 50,
50 = 5x/6 after sol x= 60 it means A can do in 60 min and B 300 min.
A finish work in x day and B can 5x day. Then we can do A+B= 1/x +1/5x.
We have A+B = 50,
50 = 5x/6 after sol x= 60 it means A can do in 60 min and B 300 min.
Jack said:
8 years ago
Can anyone explain me why the step 3/2*60 used. I couldn't get the logic of finding difference as 2.
Shaman said:
8 years ago
Please provide the solution of if A is 5 times better than B together they complete the work in 50 min then B alone can do the work in how many minutes.
Biplab sarkar said:
8 years ago
Here given k=3, n=60.
So formula is -> kn/ (k^2-1) =3*60/ (3^2-1) =180/8=22 1/2 days.
So formula is -> kn/ (k^2-1) =3*60/ (3^2-1) =180/8=22 1/2 days.
Rohi said:
8 years ago
Ratio of times taken by A and B = 1:3.
Means B will take 3 times which A will do in 1 time.
If difference of time is 2 days, B takes 3 days,
If the difference of time is 10 days, B takes (3/2) * 10 =15 days.
Means B will take 3 times which A will do in 1 time.
If difference of time is 2 days, B takes 3 days,
If the difference of time is 10 days, B takes (3/2) * 10 =15 days.
Saikrishna said:
8 years ago
a b
x 3x
2x=60 so x=30
total work=3*30=90
Ans=90/4=22 1/2.
x 3x
2x=60 so x=30
total work=3*30=90
Ans=90/4=22 1/2.
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