Aptitude - Time and Work - Discussion

Nice exp. Harsha.

Hey its simple to understand.
Days taken by B = x
Days taken by A= x - 60
Their time taken proportio is 1:3
so,
x - 60/ x = 1/3
x=90;
So A will do the work in = 30 days
abd B in 3x= 3*30=90 days,
and u can find their 1 day's work and ad it.
Simple :)

Hi friends,

Given A:B=1:3

Therefore B=3A--------equation 1

let B can do a work in x days.

then A can do the same work in (x-60) days.

then B=3A
x=(x-60)3

therefore x=90 days

therefore B can do a work in 90 days.

and A will do a work in 90-60=30 days.

I tell that A is thrice as good as B so it should be 3:1 na.

Am I right?

We can use a simple formula here:[(KL)/k squqre-1)]

-->here K=3(efficiency),L=60(time) so (3*60/(3*3)-1)=>180/8=221/2

THANK U SHEETAL,your short cut method is simply super.there is no words to say

If difference of time is 60 days 3*60/2 = 90 days.

I can't get this step?

Please explain.

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.