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:
283 comments Page 29 of 29.
Yash Sangle said:
3 months ago
3/1 = (B)/(B-60).
As work done and time are inversely related,
So, B=90, A=30.
(1/90 + 1/30) = (2/45),
So, 22 1/5.
As work done and time are inversely related,
So, B=90, A=30.
(1/90 + 1/30) = (2/45),
So, 22 1/5.
(2)
Mishra said:
1 month ago
Given: A takes 60 days less than B.
So, let A takes 90days,
B takes 30days.
LCM of 90, 30 = 180 and effeciency of A = 2 (180/90), B = 6 (180/30);
Both work together A + B = (2+6) = 8;
So, total work = 180(LCM);
total days = work/efficiency of both.
= 180/8 = 22.5.
So, let A takes 90days,
B takes 30days.
LCM of 90, 30 = 180 and effeciency of A = 2 (180/90), B = 6 (180/30);
Both work together A + B = (2+6) = 8;
So, total work = 180(LCM);
total days = work/efficiency of both.
= 180/8 = 22.5.
(6)
Lalith kumar said:
1 month ago
First, A is thrice as good as B means.
If a takes a day to complete work, then b takes 3 days to complete the same work.
Here, time is inversely proportional to work.
So if b takes time T to complete, then a takes T/3 to complete.
In question, they mentioned that the time diff is 60 days.
So, T - T/3 = 60.
2T/3 = 60.
T = 90.
Now, calculate the combined work and how many days it will take.
1/30 + 1/90 = 2/45 = 22.5.
If a takes a day to complete work, then b takes 3 days to complete the same work.
Here, time is inversely proportional to work.
So if b takes time T to complete, then a takes T/3 to complete.
In question, they mentioned that the time diff is 60 days.
So, T - T/3 = 60.
2T/3 = 60.
T = 90.
Now, calculate the combined work and how many days it will take.
1/30 + 1/90 = 2/45 = 22.5.
(2)
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