Question 419037
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The speed of a boat in still water is 5 miles per hour. If the boat travels 3 miles downstream 
in the same amount of time it takes to travel 1.5 miles upstream, what is the speed of the current?
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        The solution and the answer in the post by @mananth both are incorrect.

        I came to bring a correct solution.



<pre>
Let x be the speed of the current.


The time equation is

    {{{3/(5+x)}}} = {{{1.5/(5-x)}}}.


To solve, cross multiply and then simplify

    3*(5-x) = 1.5*(5+x),

    15 - 3x = 7.5 + 1.5x,

    15 - 7.5 = 3x + 1.5x,

       7.5   =    4.5x

         x   =  7.5/4.5 = 5/3.


<U>ANSWER</U>.  The speed of the current is  5/3 miles per hour.
</pre>

Solved correctly.