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

Question

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

A. 20 days

B. 22 1/2 days

C. 25 days

D. 30 days

How do we approach towards these kinds?

Answer 1

Let $v$ be the working speed of $B$. Then, the working speed of $A$ is $3v$. The working speed of $A$ and $B$ together is $4v$.

Now, the time $A$ spends is $t$ (in days), and the time $B$ spends is $t+60$.

Since the speed and the time are inversely proportional, their product is constant, so $3v\cdot t=v(t+60)$.

Can you continue?

Answer 2

Let A be X where as b = 3x. So, 3x – x = 60. x = 30. a = 30, b = 90.

Together they can do the work in 22 (1/2) days.

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

Answer 3

2x= 60 therefore x =30 implies a is 30 b is 90 lcm of 30 90 is 90 so a work 3 units b work 1 units so total work 4 units per a day so 90units/4units is your days

Answer 4

Implication & Assumption:

If A is thrice as good as B, then there are 2 implications:

i) A shall be able to do three times the work done by B in the same time. So let's say if B produces 1 unit in a day, A will produce 3 units

ii) A must be able to finish the same job in one-third of the time taken by B. So let's say if A takes X days to complete the work, B will do it in 3X days

Working:

Since A finishes the job in 60 days less, from (ii) we get: 3X - X = 60

So, X = 30 (A finishes the work in 30 days and B in 90 days)

Now from (i), since A produces 3 units per day in 30 days he must produce 90 Units (same way, B shall produce 90 units in 90 days)

Thus, total Work = 90 units

Final Step:

When working together, A & B will jointly produce 4 units per day. So to make 90 units they will need 90/4 = 22.5 day

Thus they will complete the work in 22.5 days (Answer).