Aptitude - Time and Work - Discussion

3x - x=60
2x = 60
x = 30
B = 3x = 3 x 30 = 90.
A+B = 1/30 + 1/90,
= 3 + 1/90,
= 4/90,
= 2/42,
= 45/2,
= 22 1/2.

Assume B can do it in x days.
So A can in x/3 days.
x - x/3 = 60.
then x = 90.
So B can do the work in 90 days.
A can do it in 90/3 = 30 days.
A and B together can do it in 90 * 30/90 + 30 = 22.5 (Ans).

A takes time = x days.
So, B takes time = 3x days
Now, 3x - x = 60 days
X = 30
3x = 90
1/30 + 1/90 = 1/20 (working together in 1 day).
So, They can do the whole work in 20 days.

Suppose A takes x days to complete the work.
Therefore, B will take 3x days.
Now, x = 3x- 60.
x= 30 days.

Thus A takes 30 days and B takes 90 days.
Therefore work done by both in 1 day will be (1/30 + 1/90) = 4/90.

Therefore they take (90/4) = 22.5 days to complete the work.

A is thrice as good as workman as B and therefore can finish a job in 60 days less than B. Working together, they can do it in:

A = 3x, B= 1x ----> {1}
Here A's efficiency = 3.
B's efficiency = 1.

The Sum of their efficiency is 4 (we will need this later on).

According to the question:
A = 3x - 60.

Therefore 1 day's work of A and B is:
1/(3x-60) = 1/(x).
By solving we get x = 30
By putting the value of x in eqn {1}
We get A= 3 X 30 = 90 days.
B = 30 days.

By working together, they can do it in:
90/4 days.
By further solving, we get 22 1/2 days.

Finding the days for B and A:

The ratio difference is 2 and the day difference is 60.

So, for every single inc in ratio, it will increase by 30 days.

From this, we can say that A is 30 days and B is 90 days (1:3 time ratio).

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.