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 5 of 29.
Sunny said:
1 decade ago
A is thrice as good as workman as B means 1:3(Ratio)
Therefore A is able to finish a job in 60 days less than B
So A= 1/60 and B=1/60 .....(Given)
According to the ratio
A=1/60 B=1/3*60 (As we are calculating by days)
So Now A = 1/60 < B = 1/90 (A finishes work less than B)
Working together, they can do it in:
1/A+B = 1/60 + 1/90 (As we are calculating by days))
1/A+B = 2/45
So
A+B = 45/2 Days
Option (B) is the correct ans
Therefore A is able to finish a job in 60 days less than B
So A= 1/60 and B=1/60 .....(Given)
According to the ratio
A=1/60 B=1/3*60 (As we are calculating by days)
So Now A = 1/60 < B = 1/90 (A finishes work less than B)
Working together, they can do it in:
1/A+B = 1/60 + 1/90 (As we are calculating by days))
1/A+B = 2/45
So
A+B = 45/2 Days
Option (B) is the correct ans
Ramesh said:
10 years ago
Time ratio between A and B is 1:3.
A/B = 1/3------ (1).
B takes thrice the time taken by A.
A-B = 60 from A = B+60--- (2).
BY substituting (2) in (1).
Then get time taken by B to finish work in 90 days.
From (1) you get time taken by A to finish work in 30 days.
A's 1 day work is = 1/30.
B's 1 day work is = 1/90.
(A+B) 1 day's work is = (1/30+1/90) = 2/45.
Then time taken by the A and B working together is 45/2.
A/B = 1/3------ (1).
B takes thrice the time taken by A.
A-B = 60 from A = B+60--- (2).
BY substituting (2) in (1).
Then get time taken by B to finish work in 90 days.
From (1) you get time taken by A to finish work in 30 days.
A's 1 day work is = 1/30.
B's 1 day work is = 1/90.
(A+B) 1 day's work is = (1/30+1/90) = 2/45.
Then time taken by the A and B working together is 45/2.
Nithya said:
1 decade ago
Lets B takes x days to complete the Work,
Then B 's Capacity ==>1/x.
A is 3 times as good as A so A'S capacity is 3/x.
Then Time Taken by B is = x/1.
Time taken by A is = x/3.
Time difference (x-x/3)=60.
Which gives x = 90.
Time taken By B = 90.
Time taken By A = 30.
(A's Work +B's Work) 1 day Work = (1/30)+(1/90).
= 4/90.
Then Time taken to complete work is 90/4 ==> 22.5 days.
Then B 's Capacity ==>1/x.
A is 3 times as good as A so A'S capacity is 3/x.
Then Time Taken by B is = x/1.
Time taken by A is = x/3.
Time difference (x-x/3)=60.
Which gives x = 90.
Time taken By B = 90.
Time taken By A = 30.
(A's Work +B's Work) 1 day Work = (1/30)+(1/90).
= 4/90.
Then Time taken to complete work is 90/4 ==> 22.5 days.
Adheer said:
4 years ago
If B completes the work in X days, then A completes the work in X-60 days.
A is thrice good as workman as B then, the ratio of the time taken to finish the same work is 1:3
Then,
(X-60) : X :: 1 : 3
Solving this, X = 90
Means B finish the work in 90 days and A finishes the work in 30 Days,
Working together, their 1-day work,
1/90 + 1/30 = 4/90 = 2/45.
Mean working together, they finish the work in 45/2 = 22(1/2) days.
A is thrice good as workman as B then, the ratio of the time taken to finish the same work is 1:3
Then,
(X-60) : X :: 1 : 3
Solving this, X = 90
Means B finish the work in 90 days and A finishes the work in 30 Days,
Working together, their 1-day work,
1/90 + 1/30 = 4/90 = 2/45.
Mean working together, they finish the work in 45/2 = 22(1/2) days.
Raman(UIET,KUK) said:
1 decade ago
Guys check this out and don't be confused....
as we know A is 3 time better than B and A takes 60 days less than B so, time taken by A: time taken by B= 1:3
= b-60:b ( suppose time by B is b)
by cross multiply, 3b-180=b
i.e. b=90 so time taken by B=90
and time taken by the A is=90-60= 30
as we know A is 3 time better than B and A takes 60 days less than B so, time taken by A: time taken by B= 1:3
= b-60:b ( suppose time by B is b)
by cross multiply, 3b-180=b
i.e. b=90 so time taken by B=90
and time taken by the A is=90-60= 30
Poornachandran said:
1 decade ago
Guys,
I'll tell by simple method.
Given, A is thrice of B.
So A = 3B---->(1).
A's 1 day work is A=1/60--->(2).
Substitute (2) in (1),
A=3B.
We get,
3B=1/60.
B=1/180.
In question they asked A+B=how many working days?
We know A and B values.
Add A and B.
1/60+1/180=1/Work days.
Take L.C.M.
3+1/180=1/Work days.
4/180=1/work days.
1/45=1/work days.
Work days=45.
By fraction we can write 22 1/2 days.
I'll tell by simple method.
Given, A is thrice of B.
So A = 3B---->(1).
A's 1 day work is A=1/60--->(2).
Substitute (2) in (1),
A=3B.
We get,
3B=1/60.
B=1/180.
In question they asked A+B=how many working days?
We know A and B values.
Add A and B.
1/60+1/180=1/Work days.
Take L.C.M.
3+1/180=1/Work days.
4/180=1/work days.
1/45=1/work days.
Work days=45.
By fraction we can write 22 1/2 days.
Nilu said:
10 years ago
A is thrice good as B.
So, ratio of work done is 3:1 and A taken 60 days less as compare to B.
Let time taken by B is x so time taken by A is x-60.
So 3:1::x:x-60.
3x-180 = x. So 2x = 180 and x = 90.
Time taken by B = 90 days so time taken By A is 30 days.
A's one day work = 1/30 and B's one day work is 1/90.
Total work done by both A and B in one day = 1/30+1/90.
= 3+1/90 = 4/90 = 2/45 = 22.5 days.
So, ratio of work done is 3:1 and A taken 60 days less as compare to B.
Let time taken by B is x so time taken by A is x-60.
So 3:1::x:x-60.
3x-180 = x. So 2x = 180 and x = 90.
Time taken by B = 90 days so time taken By A is 30 days.
A's one day work = 1/30 and B's one day work is 1/90.
Total work done by both A and B in one day = 1/30+1/90.
= 3+1/90 = 4/90 = 2/45 = 22.5 days.
SAMANTH KUMAR said:
6 years ago
Let A=X ,B=X+60 (GIVEN A TAKES 60 DAYS LESS THAN B,I CONSIDERED B TAKES 60 MORE DAYS THAN A).
Now, LCM OF X,(X+60) = X*(X+60),
Efficiency of A=(X*(X+60)) / X = X+60,
Efficiency of B=(X*(X+60)) / (X+60) = X.
Total work of A&B = (X(X+60))/(X+X+60),
We have A=3B (GIVEN).
X = 3(X+60),
X = 30.
Put in the equation and get the answer 45/2 =22(1/2).
Now, LCM OF X,(X+60) = X*(X+60),
Efficiency of A=(X*(X+60)) / X = X+60,
Efficiency of B=(X*(X+60)) / (X+60) = X.
Total work of A&B = (X(X+60))/(X+X+60),
We have A=3B (GIVEN).
X = 3(X+60),
X = 30.
Put in the equation and get the answer 45/2 =22(1/2).
Ram said:
9 years ago
Guys, this is pretty simple.
Given A : B = 3 : 1, difference in time taken is 2.
Let us consider it as 2 parts.
Then it's also given that A can complete the work with 60 days gap to B. Hence we can equate these 2 parts to 60 days.
Therefore 2 parts = 60 days.
A's part is 1 parts = 30 days.
B's part is 3 parts = 90 days.
Rest you know.
Hope you intelligent guys understand :).
Given A : B = 3 : 1, difference in time taken is 2.
Let us consider it as 2 parts.
Then it's also given that A can complete the work with 60 days gap to B. Hence we can equate these 2 parts to 60 days.
Therefore 2 parts = 60 days.
A's part is 1 parts = 30 days.
B's part is 3 parts = 90 days.
Rest you know.
Hope you intelligent guys understand :).
Sambhav said:
8 years ago
Hi guys.
It is given that A is thrice efficient then B then the efficiency of A is 3x and that of Y is x. then no of days are For A is(60-y) and for B is y. Then total work done is constant then
3x*(60-y) = x * y.
Then y = 45.
Then total work done by A is 45 X.
And rate of work of A and B will be 3x and x and if they work together the rate will be 4X.
So no of days will be = 45/4.
It is given that A is thrice efficient then B then the efficiency of A is 3x and that of Y is x. then no of days are For A is(60-y) and for B is y. Then total work done is constant then
3x*(60-y) = x * y.
Then y = 45.
Then total work done by A is 45 X.
And rate of work of A and B will be 3x and x and if they work together the rate will be 4X.
So no of days will be = 45/4.
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