SOLUTION: the time required to complete an engine overhaul varies inversely as the number of people who work on the job. it takes 4 hours for 6 students to complete an engine overhaul. if th

Algebra ->  Rate-of-work-word-problems -> SOLUTION: the time required to complete an engine overhaul varies inversely as the number of people who work on the job. it takes 4 hours for 6 students to complete an engine overhaul. if th      Log On


   



Question 1200701: the time required to complete an engine overhaul varies inversely as the number of people who work on the job. it takes 4 hours for 6 students to complete an engine overhaul. if they all work at the same rate, how long would it take 2 students to complete the job?
Found 2 solutions by Theo, ikleyn:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
y = k/x is the inverswe proportion formula.
k is the constant of variation.
y = number of hours to finish the job.
x = the number of people required.
when 6 people are working, the job is finished in 4 hours.
formula becomes 4 = k/6
solve for k to get k = 24
when 2 people are working, the formula becomes y = 24/2.
solve for y to get y = 12
6 people can do the job in 4 hours.
2 people can do the job in 12 hours.
you can also use the people * rate * time = quantity formula.
when 6 people can do the job in 4 hours, you get:
6 * r * 4 = 1
6 is the number of people.
r is the rate that each person works at
4 is the number of hours.
1 is the quantity of work performed (1 job)
solve for r to get r = 1/24 of the job per person
when the number of people is 2 and the rate per person remains the same, the formula bgecomes 2 * 1/24 * t = 1
solve for t to get t = 1 * 24 / 2 = 12
your solution is 2 people can finish the job in 12 hours.


Answer by ikleyn(52748) About Me  (Show Source):
You can put this solution on YOUR website!
.
The time required to complete an engine overhaul varies inversely as the number of people who work on the job.
it takes 4 hours for 6 students to complete an engine overhaul.
If highlight%28cross%28they%29%29 highlight%28cross%28all%29%29 students work at the same rate, how long would it take 2 students to complete the job?
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The original formulation was  ABSOLUTELY  INCORRECT  (at the level to call for urgent medical assistance)
so I edited it to make sense - - - from nonsense.


                        The answer lies at the surface.


For 2 students, it will take three times as much time as it takes for 6 students.


When people come with such primitive questions, I get trouble: what are they taught in school ?


And how their minds work ?


And who really teaches them in such terrifying way ?