The time to complete a job or some jobs varies directly with the number
of jobs and inversely with the number of workers:
Five workers have been hired to complete a job.
Workers = 5, Jobs = 1, Time required = T
If one additional worker is hired,
they could complete the job 10 days earlier.
Workers = 6, Jobs = 1, Time required = T-10
Solve that and get k=300 and T=60 days
If the job needs to be completed 32 days earlier, how many additional workers should be hired?
Let A = the number of additional workers (additional to the 5)
Solve that for A and it comes out a fraction so since they can't
hire part of a worker, they'd need to hire 6 more workers.
Answer: 6 additional workers.
Edwin
.
Five workers have been hired to complete a job. If one additional worker is hired,
they could complete the job 10 days earlier. If the job needs to be completed 32 days earlier,
how many additional workers should be hired?
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I am 999% sure that the problem in the post is printed incorrectly and has a typo.
My interior voice tells me, and I am 99% sure that the correct formulation is THIS
Five workers have been hired to complete a job. If one additional worker is hired,
they could complete the job 10 days earlier. If the job needs to be completed days earlier,
how many additional workers should be hired?
I will solve the problem in this edited formulation.
SOLUTION
Let "a" be the rate of work of one worker per day.
Then the number of days for 5 workers to complete the job is ;
the number of days for 6 workers to complete the job is .
Thus, we can write this time equation
- = 10 days. (1)
It implies
- = 10,
= 10,
a = . (2)
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| Thus, we found that under given condition the rate of work |
| is 1/300 of the job per day for each worker. |
+----------------------------------------------------------------+
Now we want to find the number n of additional workers (to 5 workers) to complete
the job 32 days earlier. For it, we write similar time equation to (1)
- = 30.
Substitute here a = 1/300, based on (2). You will get
- = 30.
To solve, simplify step by step. You will get
60 - = 30,
60 - 30 = ,
30 =
5 + n =
5 + n = 10.
n = 10 - 5 = 5.
+----------------------------------------------------------------+
| Second part of the solution can be worded in different way. |
+----------------------------------------------------------------+
We just found that the rate of work of one worker is 1/300 of the job per day.
It means that the entire job is 300 man-days.
5 workers can complete this job in 300/5 = 60 days.
We want the job be complete in 60-30 = 30 days.
For it, 300/30 = 10 workers are needed, hence, 10 - 5 = 5 workers should be added.
ANSWER. 5 workers should be hired in addition to the original 5 workers to complete the job 32 days earlier.
Solved.