SOLUTION: If m men can do a job in d days,how long will it take (m+r)?

Algebra ->  Equations -> SOLUTION: If m men can do a job in d days,how long will it take (m+r)?      Log On


   

Question 1010284: If m men can do a job in d days,how long will it take (m+r)?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
One man will take +m+ times as long
to do the same job, so, the rate of working
for 1 man is:
[ 1 job ] / [ d * m days ] = +1%2F%28+d%2Am+%29+
--------------------
More men will get the job done faster, so the new rate is
[ m + r men ] x [ rate for 1 man ] = +%28+m%2Br+%29+%2F+%28+d%2Am+%29+
--------------------
Now convert this to [ 1 job ] / [ time to do the job ]
by dividing top and bottom by +m+%2B+r+
---------------------------
+m+%2B+r+ men will take +%28+d%2Am+%29+%2F+%28+m+%2B+r+%29%29%29+ days
to do the job
------------------
You can get a 2nd opinion on this. I think I'm OK though