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.
G.P. said:
1 decade ago
SIMPLE AND BEST WAY
since a is thrice better than b
hence a:b=1:3
similarly a takes 60 days less than b
hence a:b=(b-60):b=1;3
cross multiplication n we get
3b-180=b hence b=90days hence a=30days
1/90+1/60=4/90 hence total daysreciprocal 90/4=45/2
since a is thrice better than b
hence a:b=1:3
similarly a takes 60 days less than b
hence a:b=(b-60):b=1;3
cross multiplication n we get
3b-180=b hence b=90days hence a=30days
1/90+1/60=4/90 hence total daysreciprocal 90/4=45/2
Kavitalodhi said:
7 years ago
In the question clearly, say that A takes 60 days less than B.
So A can do the work in B-60 days,
And time ratio of A:B = 1:3,
1/3=B-x/B =>B=90,A=30.
So, A and B can do the work together 1/30+1/90 =>2/45,
Mix fraction of 2/45 is 22 1/2.
So A can do the work in B-60 days,
And time ratio of A:B = 1:3,
1/3=B-x/B =>B=90,A=30.
So, A and B can do the work together 1/30+1/90 =>2/45,
Mix fraction of 2/45 is 22 1/2.
Mahesh said:
9 years ago
Let consider B can do work in n days.
1 days work of B = 1/n.
So, A = n - 60.
1 day work of A =1/ (n - 60).
As given A = 3b.
1/ (n - 60) = 3 * (1/n).
n = 90.
B can do work in 90 days.
So A can do in 30 days.
Both = (1/30) + (1/90).
= 22 (1/2).
1 days work of B = 1/n.
So, A = n - 60.
1 day work of A =1/ (n - 60).
As given A = 3b.
1/ (n - 60) = 3 * (1/n).
n = 90.
B can do work in 90 days.
So A can do in 30 days.
Both = (1/30) + (1/90).
= 22 (1/2).
Nirmala Rai said:
5 years ago
Ratio of A:B=1:3(efficiency).
=3:1(time will be opposite of efficiency).
Time difference between A:B=2.
2 denotes =60,
1 denotes=60/2=30 A,
3 denotes =60/2*3=90 B calculate L. C. M of A &B = 90,
A+B=90/4= 22(1/2)-Ans.
=3:1(time will be opposite of efficiency).
Time difference between A:B=2.
2 denotes =60,
1 denotes=60/2=30 A,
3 denotes =60/2*3=90 B calculate L. C. M of A &B = 90,
A+B=90/4= 22(1/2)-Ans.
(1)
SIBAJI MALLIK said:
2 years ago
A : B
1 : 3.
Difference = 2.
i.e 2 part = 60 (given),
1 part= 60/2 = 30.
A can do it in 30 days.
B can do it in 90 days.
A's 1 day's work= 1/30 and,
B's 1 day's work= 1/90,
A+B 1 day's work = 1/30 + 1/90 = 2/45.
They can do it in 45/2 days.
1 : 3.
Difference = 2.
i.e 2 part = 60 (given),
1 part= 60/2 = 30.
A can do it in 30 days.
B can do it in 90 days.
A's 1 day's work= 1/30 and,
B's 1 day's work= 1/90,
A+B 1 day's work = 1/30 + 1/90 = 2/45.
They can do it in 45/2 days.
(108)
Vamshidhar said:
10 years ago
In the explanation, said that,
"If difference of time is 60 days, B takes (3/2*60) = 90 days.
My opinion is if A can complete work in 60 days then B should complete work in 3*60 = 180 days but not in 90 days.
Can anyone explain this part?
"If difference of time is 60 days, B takes (3/2*60) = 90 days.
My opinion is if A can complete work in 60 days then B should complete work in 3*60 = 180 days but not in 90 days.
Can anyone explain this part?
Harsha said:
1 decade ago
Easy method :
A can completed in x days
B can in 3x days then
A = B-60 (A can do in 60 days less than B )
=> x=3x-60 => x= 30 =>
A=30, B=90
Then together work done is (1/30+1/90) = 2/45.
Finally total work done is 45/2.
A can completed in x days
B can in 3x days then
A = B-60 (A can do in 60 days less than B )
=> x=3x-60 => x= 30 =>
A=30, B=90
Then together work done is (1/30+1/90) = 2/45.
Finally total work done is 45/2.
Nil said:
10 years ago
A 1x
-- = --- (RATIO OF TIME)
B 3x
And difference is given 60 days.
3x-1x=60.
1x = 30 days for A.
3x = 90 days for B.
I don't remember but I think I have posted the another method up above long time before.
-- = --- (RATIO OF TIME)
B 3x
And difference is given 60 days.
3x-1x=60.
1x = 30 days for A.
3x = 90 days for B.
I don't remember but I think I have posted the another method up above long time before.
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.
Esrak Ahmed Kafi said:
8 years ago
Let B can do it in 3x days.
So, A can do it in X days.
According to Question,
3x-x = 60.
So, X = 30.
So, A can do it 30 days while B can do it in 90 days.
Now in (1/30+1/90) days A & B can together do the work.
=45/2 = 22.5 days.
So, A can do it in X days.
According to Question,
3x-x = 60.
So, X = 30.
So, A can do it 30 days while B can do it in 90 days.
Now in (1/30+1/90) days A & B can together do the work.
=45/2 = 22.5 days.
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