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:
284 comments Page 18 of 29.
Sanky said:
5 years ago
A:B = 1:3.
B = 3A.
Difference is 60days,
therefore B - A = 60,
3A - A = 60,
2A = 60,
A = 30 & thus B = 90.
Now, 1/30 + 1/90 = 22.5.
B = 3A.
Difference is 60days,
therefore B - A = 60,
3A - A = 60,
2A = 60,
A = 30 & thus B = 90.
Now, 1/30 + 1/90 = 22.5.
Atharv Pathak said:
5 years ago
W1/w2 = d2/d1.
W1 = 3w2.
And d1 = d2-60.
So,
3w2/w2 = d2/d2-60,
d2 = 90,
d1 = d2 - 60 = 90 - 60 = 30.
1/90 + 1/30 = 1/22.5.
Ans 22 * 1/2.
W1 = 3w2.
And d1 = d2-60.
So,
3w2/w2 = d2/d2-60,
d2 = 90,
d1 = d2 - 60 = 90 - 60 = 30.
1/90 + 1/30 = 1/22.5.
Ans 22 * 1/2.
(1)
Priya said:
1 decade ago
No need to do all that simply guess numbers 30 & 90 which is satisfying this then without using pen we can get answer 22.5 days.
Dipak said:
9 years ago
Guys. I'm giving simple approach.
3x - x = 60
x = 30
So respective days are 90 and 30.
Total days together = 30 * 90/120 = 22.5.
3x - x = 60
x = 30
So respective days are 90 and 30.
Total days together = 30 * 90/120 = 22.5.
Sunil reddy said:
1 decade ago
We can use a simple formula here:[(KL)/k squqre-1)]
-->here K=3(efficiency),L=60(time) so (3*60/(3*3)-1)=>180/8=221/2
-->here K=3(efficiency),L=60(time) so (3*60/(3*3)-1)=>180/8=221/2
Akansha said:
1 decade ago
B takes 3 times more days than A.
i.e. B=3A.
So. B-A=60.
3A-A=60 =>.
A=30.
B=90.
Now calculate 1 day work of A and B.
i.e. B=3A.
So. B-A=60.
3A-A=60 =>.
A=30.
B=90.
Now calculate 1 day work of A and B.
Dipa said:
10 years ago
3x:1x
=> 3x - 1x = 60.
=> 2x = 60.
=> x = 30.
=> 3x = 90.
A+b together work = 90 * 30 / 90 + 3.
=> 2700 / 120 = 22.5 days.
=> 3x - 1x = 60.
=> 2x = 60.
=> x = 30.
=> 3x = 90.
A+b together work = 90 * 30 / 90 + 3.
=> 2700 / 120 = 22.5 days.
Omkar Raut said:
5 years ago
A:B = 1 : 3.
Let's say A's work is x, then x : 3x.
Now, 3x - x = 60.
Given in question.
2x = 60, x = 30
Now,A = 30, B = 90.
Let's say A's work is x, then x : 3x.
Now, 3x - x = 60.
Given in question.
2x = 60, x = 30
Now,A = 30, B = 90.
Yash Sangle said:
5 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.
(10)
Satyawan said:
1 decade ago
The explanation given above is very difficult to understand please try to explain the concepts as simple as possible.
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