Aptitude - Time and Work - Discussion

Ratio of times taken by A and B = 1 : 3.

That is If A takes 1 day B takes 3 days
Time Difference is 3-1 = 2 days

Here is the tricky part :
If A takes 1/2 day B takes 3/2 days
Time Difference is 3/2 - 1/2 = 1 days

When time difference is 60 days (Just mulitply by 60)
A takes 60/2 and B takes 3*60/2

So, A takes 30 days to do the work.
and B takes 90 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 = (1/30 + 1/90)= 4/90 = 2/45

A and B together can do the work in 45/2 = 22+1/2

Awesome explanation HARSHA

Thanks Showry for given the simple and correct ans.

Thanks harsha.

A will finish the work 60 days lesser than B.

What is it mean please explain?

@Neeraj-A will finish the work 60 days lesser than B,means if B takes 60 days to complete the work,A takes 1 day.

Another easy way 2 find out:

1st put the ratio i.e.1:3(A:B)
2nd the condition given here is A can work less than 60 days

So, find out the probability that matches with the ratio condition(A&B must be difference 60 here) for eg:let we take as A as 20 therefore B must be 60(here we get the difference as 40 only)according to 1:3 which cant satisfy

The given condition(A less than B by 60 days) suppose you take A as 30 means you get B as 90 which is greater than 60 days
of A....A=30 B=90 A's 1 day work=1/30

B's 1 day work=1/90 A+B's 1 day work =1/30+1/90=4/90 here they are not given to find out as 1day work...so take as 90/4=22.5 <==> 22(1/2).

Nice formula @Sheetal.

Thanks sheetal.

@sheetal
do not able to understand how you get that formula to calculate the time i.e.
K*X/K^2-1