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 6 of 29.
MOSA said:
6 years ago
Let a did this work in X days.
B can do it in 3x days.
X+60=3x.
X=30.
It means A can complete this work in 30 days and B in 90 days;
Capacity of;
A is 3.
B is 4.
A+B= 4.
TIME =90/4.
B can do it in 3x days.
X+60=3x.
X=30.
It means A can complete this work in 30 days and B in 90 days;
Capacity of;
A is 3.
B is 4.
A+B= 4.
TIME =90/4.
Abhijith said:
6 years ago
Can someone provide a solution for this problem using percentages or the efficiency ration ?
Priti said:
6 years ago
***shortcut method******
D= no of days.
n= n times as fast.
D*n/n^2-1
60*3/3^2-1
180/9-1
180/8=90/4=22 1/2.
D= no of days.
n= n times as fast.
D*n/n^2-1
60*3/3^2-1
180/9-1
180/8=90/4=22 1/2.
Dinesh said:
6 years ago
Please tell how A is working 30 days. How we calculate I don't understand.
Aravind said:
6 years ago
Hi, friends, it's a bit tricky.
First, they found the time difference to do work between a and b.
Because the data we have is time difference in qn for 60 days consider.
Then. If a takes 1 day. B takes 3 days. So.
For 2 days time difference : 3 days for b
Then multiply both sides by 30 since the time difference is given
For 60 days time difference: 90 days of b.
I hope you all get it.
Then use ratio. A takes 30 days to complete work.
First, they found the time difference to do work between a and b.
Because the data we have is time difference in qn for 60 days consider.
Then. If a takes 1 day. B takes 3 days. So.
For 2 days time difference : 3 days for b
Then multiply both sides by 30 since the time difference is given
For 60 days time difference: 90 days of b.
I hope you all get it.
Then use ratio. A takes 30 days to complete work.
Rohan said:
6 years ago
A and B
Work 3:1
Time 1:3
i.e. 30:90 ......multiply by 30.
And also they have given that the difference between the time taken to complete the work is 60.
Hence when A and B time to work together,
1/30+ 1/90 = 2/45,
Defer for A and B to complete the entire work they require 45/2 which is equivalent to 22 and A half-day.
Work 3:1
Time 1:3
i.e. 30:90 ......multiply by 30.
And also they have given that the difference between the time taken to complete the work is 60.
Hence when A and B time to work together,
1/30+ 1/90 = 2/45,
Defer for A and B to complete the entire work they require 45/2 which is equivalent to 22 and A half-day.
Sanishk said:
6 years ago
What is wrong with the below step?
A's 1-day work = 1/y.
Then, B's 1-day work = 1/3y.
Now,
A completes work before 60 days compared to B.
So,
1/y - 1/3y = 1/60
2/3y = 1/60
y = 40.
i.e., A completes in 40 days and B completes in 120 days,
Now, working together they complete in
1/A + 1/B = 1/40+ 1/120 = 1/30.
So, Together they complete in 30 days.
A's 1-day work = 1/y.
Then, B's 1-day work = 1/3y.
Now,
A completes work before 60 days compared to B.
So,
1/y - 1/3y = 1/60
2/3y = 1/60
y = 40.
i.e., A completes in 40 days and B completes in 120 days,
Now, working together they complete in
1/A + 1/B = 1/40+ 1/120 = 1/30.
So, Together they complete in 30 days.
Yaswanth said:
6 years ago
Let's assume A completes its work in x days.
B completes in 3x days . since A is times efficient than B.
now, their difference is 60 days.
then, x-3x=60,
2x=60,
x=30,
A=30,B=90.
So, one days work of A and B together is A+B=1/30+1/90.
=4/90,
=2/45,
So one day work of A and B together is 2/45.
So A and B can complete the work in 45/2 days.
this equals to 22(1/2).
B completes in 3x days . since A is times efficient than B.
now, their difference is 60 days.
then, x-3x=60,
2x=60,
x=30,
A=30,B=90.
So, one days work of A and B together is A+B=1/30+1/90.
=4/90,
=2/45,
So one day work of A and B together is 2/45.
So A and B can complete the work in 45/2 days.
this equals to 22(1/2).
Yash said:
6 years ago
(T*T.D)/(T^2-1).
T-EFFICIENCY.
T.D-TIME DIFFERENCE.
So;
3*60/9-1 = 22.5.
T-EFFICIENCY.
T.D-TIME DIFFERENCE.
So;
3*60/9-1 = 22.5.
Neena said:
6 years ago
We can simplify it.
Assume if B worked for 90 days and
C worked for 30 days.
B's 1-day work = 1/90.
A's 1-day work = 1/30.
A+B = 4/90 work.
ie, 90/4 = 22.5.
Assume if B worked for 90 days and
C worked for 30 days.
B's 1-day work = 1/90.
A's 1-day work = 1/30.
A+B = 4/90 work.
ie, 90/4 = 22.5.
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