Aptitude - Time and Work - Discussion

3/1 = (B)/(B-60).
As work done and time are inversely related,
so, B = 90, A = 30.
(1/90 + 1/30) = (2/45),
So, 22 1/5.

A+B = (1/30 + 1/90) = 2/45.

How we are getting this?

Given: A takes 60 days less than B.
So, let A takes 90days,
B takes 30days.

LCM of 90, 30 = 180 and effeciency of A = 2 (180/90), B = 6 (180/30);
Both work together A + B = (2+6) = 8;
So, total work = 180(LCM);
total days = work/efficiency of both.
= 180/8 = 22.5.

3/1 = (B)/(B-60).
As work done and time are inversely related,
so, B=90, A=30.
(1/90+1/30)=(2/45),
So, 22 1/5.

A - 30d.
B - 90d.
lcm - 90(total work).
Efficiency of A - 3.
Efficiency of B - 1.

Total Efficiency = 4 total.

work/totalEfficiency=90/4=22.5.

Here a simple calculation is;
A takes 1 part and B takes 3 parts.
\
So A:B ratio is 1:3.
total 4p.and the difference is 2,they did work in 60 days so 60p.
4p=60.
p=15/1.
B total working days 15*3=45.
W/t is 45/2.

@All (Must read if you have any doubts)

If B takes 3 days then A takes 1 day to complete the task.

Time taken Ratio => A : B = 1 day : 3 days.

1 3 (difference is 2)

10 30 (diff 20)

30 90 (diff 60) <= Here diff is 60 days, So this is the correct ratio to be used in calculation, since it was mentioned in the given question.

A alone can finish the task in 30 days.
B alone can finish the task in 90 days.

Work done by A alone in 1 day = 1/30
Work done by B alone in 1 day = 1/90

Work done by A and B in one day (1/30 + 1/90) = 3+1/90 = 4/90

The no. of days required to complete the task by A and B is
= 90/4
= 22.5 days.

////**** Important Note: ****////

We cannot take other ratios like 1:3, 10:30, 40:120, 60:180 for the calculation. Since the diff is mentioned as 60 days.

Because, it will give different answers for each different ratios used for calculation.

If we take 1:3 => (1/1 + 1/3) = 4/3

If we take 10:30 => (1/10 + 1/30) = 4/30

If we take 40:120 = (1/40 + 1/120) = 4/120

If we take 60:180 => (1/60 + 1/180) = 4/180 ... so on.

I hope this will help you. Have a nice day!

3/1 = (B)/(B-60).

As work done and time are inversely related,
So, B=90, A=30.
(1/90 + 1/30) = (2/45),
So, 22 1/5.

First, A is thrice as good as B means.

If a takes a day to complete work, then b takes 3 days to complete the same work.

Here, time is inversely proportional to work.

So if b takes time T to complete, then a takes T/3 to complete.
In question, they mentioned that the time diff is 60 days.
So, T - T/3 = 60.
2T/3 = 60.
T = 90.
Now, calculate the combined work and how many days it will take.
1/30 + 1/90 = 2/45 = 22.5.

Hi Friends!

The statement "A is thrice as good as workman as B" states that, If A complete a work in 1 day, B will take 3 days to complete the same work.

Therefore, if A takes 1 day, B takes 3 days, the time difference is 2 days.

If the time difference is 2 days, B takes 3 days to complete the work.

Similarly if the time difference is 60 days, then B takes (3/2*60) = 90 days.

Then A takes 90 - 60 = 30 days to complete the work.

It is very simple man.