SOLUTION: If nine men take 15 days to assemble 18 machines, how many days will it take 20 men to assemble 60 machines? Clue: This problem is a combination of direct and indirect relations

Algebra ->  Rate-of-work-word-problems -> SOLUTION: If nine men take 15 days to assemble 18 machines, how many days will it take 20 men to assemble 60 machines? Clue: This problem is a combination of direct and indirect relations      Log On


   



Question 1184870: If nine men take 15 days to assemble 18 machines, how many days will it take 20 men to assemble 60 machines?
Clue: This problem is a combination of direct and indirect relations. To deal with this problem, ask yourself how the variable M(men) varies with the respected D(days); that I, will more men require more days or will more men require less days to do the job? How about M and C(machines)? Will more men produce more machines or more men produce less machines?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
135 man days for 18 machines or 7.5 man days per machine.
Therefore 60 machines need 450 man days with 20 men or 22.5 days.
9*15/18=20*x/60
20x*18=60*9*15
360x=60*9*15
6x=135
x=22.5 days
More men will require fewer days to do the same job, or more men will produce more machines, if time is held constant.