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:
292 comments Page 30 of 30.
Anom said:
3 months ago
How 30 days taken? Please explain me.
Hemanthkumar said:
2 weeks ago
Efficiency of A: B = 3:1.
TIMES RATIO = 1 : 3.
2 PARTS - 60.
And 1 PART - 30.
So, Total work done by both = A's effi * time/both efficiency.
30 * 3/4 = 22.5.
TIMES RATIO = 1 : 3.
2 PARTS - 60.
And 1 PART - 30.
So, Total work done by both = A's effi * time/both efficiency.
30 * 3/4 = 22.5.
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