Aptitude - Time and Work - Discussion

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

x = 3(x-60);
x = 3x - 180;
2x = 180;
x = 90;
B = 90 days
A = 30 days.

Work done in 1 day A and B together => 1/30 + 1/90=2/45;
Whole work is will be done 45/2=>22 1/2;

A is thrice as good as workman as B and therefore can finish a job in 60 days - question
Just think A thrice is 90;
How means;

A is thrice as b;
For A assume as x;
then B assume as 2x;
then C assume as 3x;

in question they thrice -- so we can assume thrice as 3x;
if one is 30 means.
then twice as 60.
then thrice as 90.
So , one day of the work is 1/30, then thrice day of the work is 1/90.

Working together A+B;
1/30+1/90;then.
Then take lcm it will give 90.
Then check whether the 90 is in a and b
3+1/90;
4/90;
2/45;
Then reciprocal it or div it will give 22 1/2.

Given Equation
A = 3B ---> (i)
Let B=x days --> (ii)
Given:
A = x - 60 days ---> (iii)

Compare i and iii;
x-60 = 3B (i.e B=x).
x-60 = 3x,
x = 30.
A = 3 * 30 = 90 days.
B = 30 days.
LCM 90.
A's Efficiency 1.
b's Efficiency 3.
90/3+1 = 22 1/2 days.

A takes x-60 days.
B takes x days.
If A does work in 1 day then B takes 3 days.
So,
1/(x-60) = 1/x
Solving this we get x = 90
Now, A+B can do work in 1/90 + 3/90.
We get 45/2.

a : b
1 : 3.

And x-60:x

Then 3(x - 60) = x.
3x-180 = x,
2x = 180,
x = 90.

a = 90 - 60 = 30
b = 90
1\a + 1\b = 1\30 + 1\90 = 2\45.
a + b = 45\2.
So, the answer is 22 1\2.

As A is thrice good than B then the Ratio of work done together is:

A : B
3 : 1

As A do work 60 days less than B , Suppose;
A : B
30 : 90---->LCM = 90,
(30×3)----->3u of A+1u of B =4u,
I.e 90/4 = 45/2 = 22(1/2).

A : B
1 : 3.

Difference = 2.
i.e 2 part = 60 (given),
1 part= 60/2 = 30.
A can do it in 30 days.
B can do it in 90 days.

A's 1 day's work= 1/30 and,
B's 1 day's work= 1/90,
A+B 1 day's work = 1/30 + 1/90 = 2/45.
They can do it in 45/2 days.

3x-x = 60,
x = 30.

A=90 B=30.

LCM(90,30) == 90unit.

for A -------> 1unit/day.
for B ------->3unit/day.

Total unit of work = 90/4 = 22.5.

Given A:B = 1:3 => B = 3A.'

Let assume A can complete work in x days which implies B = 3x
and also given B-A = 60 => 3x-x = 60 => 2x = 60 => x = (60/2) => 30

therefore A can complete the work in 30 days. and B can complete the work in 3*30 = 90 days
1 day work of A & B together = 1/30 + 1/90 = 4/90.

If they both do 4/90 work in one day so to complete the whole 1 work they will take;
(4/90) * x = 1.
x = 90/4 = 45/2 = 22 1/2.

Let A complete work in = x days.
B will complete work in = 3x days.

(As a is 3x sufficient so b will take 3x much time)
Also, A take 60 days less,
So days were taken by B - 60 = days taken by A
So equation will be;
3x - 60 = x,
2x = 60,
x = 30.

So A completes work in 30 days and B in 30 X x = 90
A 1-day work = 1/30,
B 1 day work = 1/90,

1 day work of A & B together = 1/30 + 1/90 = 4/90.

If they both do 4/90 work in one day so to complete the whole 1 work they will take
4/90 X x = 1.
x = 90/4 = 45/2 = 22 1/2.