Respuesta :
Answer:
4 days.
Explanation:
Given:
A company can complete a certain job in 12 days.
Another company can complete the same job in 9 days,
And the third company in 18 days.
Question asked:
In how many days can three companies, if they work together, complete the job ?
Solution:
In 12 days, a company can complete = 1 job
In 1 day, a company can complete = [tex]\frac{1}{12}[/tex] of the job ( one - twelfth part of the job)
Similarly, another company can complete in 1 day = [tex]\frac{1}{9}[/tex] of the job
And the third company can complete in 1 day = [tex]\frac{1}{18}[/tex] of the job
Now, to find number of days they will take to complete the whole job together,
In 1 day, all the three company can complete = [tex]\frac{1}{12}+\frac{1}{9} +\frac{1}{18}[/tex] of the job
By taking LCM of 12, 9 and 18 we get 36 =[tex]\frac{3+4+2}{36} =\frac{9}{36} = \frac{1}{4}[/tex] of the job
Now, [tex]\frac{1}{4}[/tex] of the job is done in = 1 day
Then the 1 whole job is done in = [tex]\frac{1}{\frac{1}{4} }[/tex] ( by unitary method )
= [tex]1\div\frac{1}{4}[/tex]
= [tex]1\times\frac{4}{1} = 4 \ days[/tex]
Therefore, three companies can complete the job in 4 days, if they work together.
Answer:
4 days require three companies to complete the job
Explanation:
Let
One company be A, another be B and third be C
Work done by A in 1 day = 1 / 12 days
Work done by B in 1 day = 1/ 9 days
Work done by C in 1 day = 1/ 18 days
So,
Work done by all three companies will be computed as:
A + B + C = 1/ 12 + 1/ 9 + 1/ 18
Taking the LCM of 12, 9, 18 , which comes 216
= 18 + 24 + 12 / 216
= 54 / 216
Now dividing 54 by 216, it will be:
= 1 / 4 days or 4 days
Therefore, the work done by all companies is 1/ 4 days, which means they need 4 days to complete the job.
