SOLUTION: if 9 men can do a work for 5 hrs a day in 16 days, in how many days will 18 men can do the work working 5 hrs

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Question 813537: if 9 men can do a work for 5 hrs a day in 16 days, in how many days will 18 men can do the work working 5 hrs
Found 2 solutions by josmiceli, josgarithmetic:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Keep everything in terms of hours
+5%2A16+=+80+ hrs
The rate of working of 9 men is:
( 1 job ) / ( 80 hrs )
---------------
Twice as many men can do the same
job in half the time, so
18 men can do 1 job in +80%2F2+=+40+ hrs
If they work 5 hrs a day,
+40%2F5+=+8+
------------
18 men can do the job in 8 days

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
First look at the one man rate per hour.
9 men for 5*16 hours_____________________1 man for 9*5*16 hours because one man must work 9 times longer.
1%2F%289%2A5%2A16%29 jobs per hour.

Now, 18 men work at the rate of 18%2F%289%2A5%2A16%29 jobs per hour.
FIVE hours?
How much of the job?
%2818%2F%289%2A5%2A16%29%29%2A5 jobs. This is 18%2F%289%2A16%29=2%2F16=1%2F8 job. That is for 1 day, 5 hours per day.

Using that rate as (1/8) job per day, how many days for 1 whole job?
Let d = number of days.
%281%2F8%29%2Ad=1
highlight%28d=8%2F1%29 or 8 days.