Question 1719: I have 2 questions!
1. The speed of a stream is 6MPH. If a boat travels 92 miles downstream in the same time that it takes to travel 46 miles upstream, what is the speed of boat in still water. ( I know the answer is 18 MPH, just need to know the solution)
2. Martha can rake the leaves in her yard in 2 hours. Her younger brother can do the job in 3 hours. How long will it take them to do the job if they work together. ( I know the answer is 5/6 hours, just need to know the solution)
Answer by longjonsilver(2297)   (Show Source):
You can put this solution on YOUR website! ok...first define speed of boat in still water to be v (or whatever letter you want).
downstream, its speed is v+6. Upstream, its speed is v-6.
Now, speed = distance/time, so:
downstream: 
upstream: 
Re-arranging these 2 and equating for t, gives:
Re-arranging again gives v=18mph
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2. using speed=distance/time as a start, where distance, d, is the area covered really...
speed of martha = d/2
speed of brother = d/3
together, their speed is  , and they cover the same space..the yard, so distance is still d...just need to find the time...
cancel the d's gives...
 , giving
or  hours.
So, hopefully, you have misread the answer. Alternatively, I have the answer wrong!!!
cheers
Jon.
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