If it takes 10 people 12 hours to do a certain job, how many hours would it take 6 people, working at the same
Man-hour required to do the job = 10*12 = 120 Man-hour required to do 1/4 0f the job = 120/4 = 30 Number of hours required to do 1/4 of the job by 6 people = 30/6 = 5 hrs. I find this method of using man-hour useful.. You can also use a method called "unitary method".
Worker a takes 8 hours to do a job. Worker b takes 10 hours to do the same job. How long should it take both a and b, working together but independently, to do the same job?
Assuming the rates are constant.Worker A is 1/8 job per hour.B is 1/10 job per hour.Convert the rate into 5/40 for A and 4/40 for B.Adding gives you 9/40 job(s) per hour.So 40/9 hours, 4 hours and 26 minutes 40 seconds
If A can finish a job in 5 hours and B can finish the same job in 10 hours, how many minutes will it take both of them together to finish the job?
A takes 5hrsB takes 10hrsWork done in 1hr by-A= 1/5th of the total workB=1/10th of the total workA and B both= (1/5)+(1/10)= 3/10th of the work=>10/3 hrs for completing work togather=(10x60)/3=200mins.•. it takes 200 mins to complete the work togather by both A and B.
If 15 workers did a job in 8 hours, how long would it take 5 workers to do half of this job?
The job 1, requires 120 man hours, 15*8=120 So half of the job would require half as many man hours of 120/2=60 man hours. To do this half job with 5 men:60 man hours divided by 5 men = 12 hours.
If 10 men can finish a job in 8 hours, how many hours will it take 12 men to finish the same job?
We will use Chain Rule to solve this question.According to Chain Rule, the work efficiency remains constant.[math]\dfrac {W}{WF \times T} [/math]= ConstantHere W = Work Done, WF = Workforce, T = Time.Let the number of hours needed be 'x'.Applying Chain Rule,[math]\dfrac {W}{10 \times 8} = \dfrac {W}{12 \times x} [/math]Or, [math]x = \dfrac {80}{12}[/math]Or, [math]\fbox {x = 6.66 Hours}[/math] (Answer)
If it takes 5 workers 12 hours to unload a truck, how long would it take 6 workers?
It would take 10 hours. The way you work this out is by working out the total number of man-hours, then dividing it by the workers. You work out the man-hours by multiplying the number of workers by the number of hours, like so: workers * time = man-hours 5 * 12 = 60 This means that it takes 60 man-hours to unload the truck. Therefore, to work out how long it would take 6 workers, we divide the man-hours by the workers: man-hours / workers = time 60 / 6 = 10 Therefore, it is 10 hours, because the truck will always take the same number of man-hours to be unloaded. Of course, this is only theoretical - it's very unlikely that the workers would be equally matched, and there would be a limit to how many workers you could use before it wouldn't work. For example, you could theoretically get 3600 workers, and unload the truck in 1 minute, but then there'd be real world issues that you'd have to take into effect (for example, there may not be a big enough door to let more workers in and out at once).
John can do a certain job in 11 hours while the same job takes Peter 15 hours. How long will it take both of them working together?
J does 1/11 work (W) per hour.P does 1/15W per hour.Together they do 1/11+1/15 W per hour.1/11W + 1/15W = 15/165W + 11/165W, or 26/165W per hour. 165/26=6 9/165 hours to do the job.
If it takes 5 workers 6 hours to complete a task how long will it take 3 workers to do the task?
Suppose 7 workers can complete a given task in 8 days. If there are 4 workers, how many days would it take for them to finish the same task? If it takes 7 workers 8 days, that means that all 7 workers together complete 1/8 of the task each day. Thus each worker completes 1/56 of the task each day. 4 workers, therefore, complete 4/56 = 1/14 of the task each day. Thus it will take them 14 days to complete the task. Now just apply the same method to your problem
If 12 men are working 8 hours a day and they complete the job in 5 days then how many men working for 10 hours a day complete the same job?
We will use Chain Rule to solve this question.According to Chain Rule, the work efficiency remains constant.[math]\dfrac {W}{WF \times T} [/math]= ConstantHere W = Work Done, WF = Workforce, T = Time.Let the number of men needed be 'x'.Applying Chain Rule,[math]\dfrac {W}{12 \times 8 \times 5} = \dfrac {W}{x \times 10 \times 5} [/math]Or, [math]x = 9.6[/math] MenSo, you need 10 men approximately. (Answer)
If 30 men do a job in 11 days, working 9 hours daily, how many hours a day do 55 men have to work in order to finish another job thrice as great in 18 days?
30 men do a job in 11 ×9 = 99 hrs.To finish thrice as great a job, they will need 99 × 3 = 297 hrs.So 1 man will need 297 × 30 = 8910 hrs.Now 55 men will need 8910 / 55 = 810 / 5 = 162 hrs in all.To complete this job in 18 days, they will need to work 162 / 18 = 9 hours a day.