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 11 of 29.
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:
9 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.
Jagadish Behera said:
3 years ago
"A" is 3 times more than" B" (efficiency)
Difference = 60 days
3x-x = 60
X = 30days This is" B"
A=3 * 30 = 90 days.
So Total work =180
A=2 WORK
B=6 WORK
A+B TOGETHER CAN DO IN 180/8 = 22.5 DAYS.
Difference = 60 days
3x-x = 60
X = 30days This is" B"
A=3 * 30 = 90 days.
So Total work =180
A=2 WORK
B=6 WORK
A+B TOGETHER CAN DO IN 180/8 = 22.5 DAYS.
(14)
Malay kanti Bhunia said:
1 decade ago
X - 3X = 60.
X = 30.
A done works 30 days and B done the work 90 days.
A work done in 1 day 1/30 part.
B work done in 1 day 1/90 part.
A and B work together in 1 day (1/30+1/90) = 2/45 part.
Time taken in this work 22.5 days.
X = 30.
A done works 30 days and B done the work 90 days.
A work done in 1 day 1/30 part.
B work done in 1 day 1/90 part.
A and B work together in 1 day (1/30+1/90) = 2/45 part.
Time taken in this work 22.5 days.
Venkatesh said:
1 decade ago
Hi friends just read, A's works 3 times than B so work ration 3:1 and time ratio will be 1:3 in the question they ask for time so 3/(3-1)*60=90.
A 3 times better 3/90=1/30(1 days work) B 1/90 1days work together 1/90+1/30=answer.
A 3 times better 3/90=1/30(1 days work) B 1/90 1days work together 1/90+1/30=answer.
Farheen Pathan said:
3 years ago
As A is thrice good than B then the Ratio of work done together is:
A : B
3 : 1
As A do work 60 days less than B , Suppose;
A : B
30 : 90---->LCM = 90,
(30×3)----->3u of A+1u of B =4u,
I.e 90/4 = 45/2 = 22(1/2).
A : B
3 : 1
As A do work 60 days less than B , Suppose;
A : B
30 : 90---->LCM = 90,
(30×3)----->3u of A+1u of B =4u,
I.e 90/4 = 45/2 = 22(1/2).
(35)
Nitin singh parihar said:
1 decade ago
Let B do the work in 'x' days.
So, A will take (x-60) days.
Now, ratio of A:B=1:3 (given in ques).
So, 1/3=x-60/x.
=> x=90 (B's 1 day work).
So, A's work=30 days.
Working together=1/30+1/90.
=45/2 days.
Easy and simple.
So, A will take (x-60) days.
Now, ratio of A:B=1:3 (given in ques).
So, 1/3=x-60/x.
=> x=90 (B's 1 day work).
So, A's work=30 days.
Working together=1/30+1/90.
=45/2 days.
Easy and simple.
Ankita said:
1 decade ago
Suppose A takes x days.
Then, B will take 3x days.
From question, 3x-x = 60.
=> x = 30.
=> A takes 30 days and B takes 90 days.
Together they will take = 30*90/30+90.
= 30*90/120.
= 90/4.
= 22.5 or 22 1/2 days (ans).
Then, B will take 3x days.
From question, 3x-x = 60.
=> x = 30.
=> A takes 30 days and B takes 90 days.
Together they will take = 30*90/30+90.
= 30*90/120.
= 90/4.
= 22.5 or 22 1/2 days (ans).
Shreya said:
7 years ago
@All.
This is the easiest & shortest!.
Let a be x whereas b = 3x.
So, 3x " x = 60. x = 30.
therefore a = 30, b = 90.
so when they work together-> 1/30+1/60 = 4/90 = 2/45.
Together they can do the work in 22 (1/2) days.
This is the easiest & shortest!.
Let a be x whereas b = 3x.
So, 3x " x = 60. x = 30.
therefore a = 30, b = 90.
so when they work together-> 1/30+1/60 = 4/90 = 2/45.
Together they can do the work in 22 (1/2) days.
Apsar Khan said:
5 years ago
If A completes the work in x days, B will do the same in 3x days.
3x - x = 60.
2x = 60.
Then x = 30 and 3x = 90.
(A + B) 's 1 day's work.
=1/30 + 1/90.
= 4/90.
So, A and B together will do the work in;
= 90/4.
=>22 and 1/2.
3x - x = 60.
2x = 60.
Then x = 30 and 3x = 90.
(A + B) 's 1 day's work.
=1/30 + 1/90.
= 4/90.
So, A and B together will do the work in;
= 90/4.
=>22 and 1/2.
(1)
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