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 |
![]() |
45 | = 22 | 1 | days. |
2 | 2 |
Discussion:
281 comments Page 12 of 29.
Sridhar said:
1 decade ago
Simple way:
A and B ratio 1:3.
Since A finishes 60 days lesser than be A takes 90 days and B takes 30 days.
So per day calculation (1/90+1/30) = 22.5 days.
A and B ratio 1:3.
Since A finishes 60 days lesser than be A takes 90 days and B takes 30 days.
So per day calculation (1/90+1/30) = 22.5 days.
Vinod Anand said:
1 decade ago
If A is thrice as good as workman B,
Than A=3B ----(1) or B=A/3 --------(2).
If A is finish a job in 60 days less than B.
Than A = B-60.
Put the value of B from Eq.(2).
A = A/3 -60
3A = A-180
2A = 180
than A = 90 Days.
Same Put the value of A in Eq.(2).
B=90/3 = 30 Days.
So Working together (A+B) = 1/90 + 1/30.
A+B = 2/45.
or A+B =45/2 = 22.5 or 22 1/2.
Answer.22 1/2 Days.
Than A=3B ----(1) or B=A/3 --------(2).
If A is finish a job in 60 days less than B.
Than A = B-60.
Put the value of B from Eq.(2).
A = A/3 -60
3A = A-180
2A = 180
than A = 90 Days.
Same Put the value of A in Eq.(2).
B=90/3 = 30 Days.
So Working together (A+B) = 1/90 + 1/30.
A+B = 2/45.
or A+B =45/2 = 22.5 or 22 1/2.
Answer.22 1/2 Days.
PARASHAR said:
1 decade ago
Simple yaar.
>A is thrice as good as workman as B and therefore is able to finish a job in 60 days=IF B TAKE 90 DAYS THEN A WILL TAKE 30 (60 DAYS LESS).
>1/30 (PLUS) 1/60=4/90==>90/4==>22. 5 SIMPLE.
>A is thrice as good as workman as B and therefore is able to finish a job in 60 days=IF B TAKE 90 DAYS THEN A WILL TAKE 30 (60 DAYS LESS).
>1/30 (PLUS) 1/60=4/90==>90/4==>22. 5 SIMPLE.
Thirupathi Malavath said:
1 decade ago
Simple method:
Say B completes the work in 'x' days.
Then A will take (x-60) days to finish the work.
Since A is thrice as good as B, 3A=B.
Therefore, 3 (x-60) =x, x=90.
B's 1 day work=1/90, A's 1 day work=1/30.
(A+B) 's 1 day work= (1/90+ 1/30) =2/45.
Therefore, both can finish the work in 45/2 days i.e., 22 1/2.
Say B completes the work in 'x' days.
Then A will take (x-60) days to finish the work.
Since A is thrice as good as B, 3A=B.
Therefore, 3 (x-60) =x, x=90.
B's 1 day work=1/90, A's 1 day work=1/30.
(A+B) 's 1 day work= (1/90+ 1/30) =2/45.
Therefore, both can finish the work in 45/2 days i.e., 22 1/2.
Ankush Rana said:
1 decade ago
A is twice as good as workman B and together they finish a piece of work in 14 days. A alone can finish the work in.
Sam said:
1 decade ago
Did they mention that difference of working time is 60 days.
Shivaram vollala said:
1 decade ago
In the given question the ration of capacity of work in day a:b is = 3:1.
So always inverse proportion to capacity and work like the way a and b can do the work ration =1:3 i.e. a's one day work = b's three days work.
So let now finish work together is imagine x.
Ratios of each person a's work = x* 1/4 = X/4. (1).
Ration of b's work = x* 3/4 = 3X/4. (2).
In the given question difference is 60 days.
So 3X/4-X/4 = 60 Days.
Solove ther x we get x = 120.
Now substitute x in (1) and (2).
W e get a's part of one day work = 30 days.
And b's part of one day work = 90 days.
Now solve the.
A and B together work = 1/30+1/90 = 4/90 =2/45.
This is and b together part of work now one day work = 45/2 = 22.5 days.
So always inverse proportion to capacity and work like the way a and b can do the work ration =1:3 i.e. a's one day work = b's three days work.
So let now finish work together is imagine x.
Ratios of each person a's work = x* 1/4 = X/4. (1).
Ration of b's work = x* 3/4 = 3X/4. (2).
In the given question difference is 60 days.
So 3X/4-X/4 = 60 Days.
Solove ther x we get x = 120.
Now substitute x in (1) and (2).
W e get a's part of one day work = 30 days.
And b's part of one day work = 90 days.
Now solve the.
A and B together work = 1/30+1/90 = 4/90 =2/45.
This is and b together part of work now one day work = 45/2 = 22.5 days.
Sudhanshu said:
1 decade ago
Why so many stories I don't know.
Its as simple as this:
A's 1 day's work = x.
B's 1 days work = x+60.
So, total one day's work is.
1/x + 1/x+60 = 1.
And you get x = 30 that is total days required for A to cmplete the work where B's value gets 90 days.
Rest you can solve.
Its as simple as this:
A's 1 day's work = x.
B's 1 days work = x+60.
So, total one day's work is.
1/x + 1/x+60 = 1.
And you get x = 30 that is total days required for A to cmplete the work where B's value gets 90 days.
Rest you can solve.
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.
Jag parvesh said:
1 decade ago
Ratio of times taken by A and B to finish a work is 1 : 3.
A:B=1:3 OR A/B=1/3 or 3A=1B --(1).
B-A = 60.
B-(1/3)B = 60 (Substituting the value of A from eq 1).
3B-B = 180 (Multiply through by 3).
2B = 180.
B = 180/2.
B = 90.
A = (1/3)*90.
A = 30.
So, A can do the job in 30 days.
Therefore, A can do 1/30 of the job per day.
And B can do the job in 90 days.
Therefore, B can do 1/90 of the job per day.
Work they can do per day:
= (1/30) + (1/90).
= (3/90)+(1/90).
= (3+1)/90.
= 4/90.
So the job will take 90/4 days, which is 45/2 or 22.5 days.
A:B=1:3 OR A/B=1/3 or 3A=1B --(1).
B-A = 60.
B-(1/3)B = 60 (Substituting the value of A from eq 1).
3B-B = 180 (Multiply through by 3).
2B = 180.
B = 180/2.
B = 90.
A = (1/3)*90.
A = 30.
So, A can do the job in 30 days.
Therefore, A can do 1/30 of the job per day.
And B can do the job in 90 days.
Therefore, B can do 1/90 of the job per day.
Work they can do per day:
= (1/30) + (1/90).
= (3/90)+(1/90).
= (3+1)/90.
= 4/90.
So the job will take 90/4 days, which is 45/2 or 22.5 days.
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