Question 1145935
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Boat travels r mile per hour in still water. The speed of the river is c miles per hour. How long will it take to travel d miles upstream?
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Upstream, boat will travel at  {{{r-c}}} {{{miles/hour}}}.


If x is amount of time of travelling asked for, then
{{{(r-c)x=d}}}

{{{highlight_green(x=d/(r-c))}}}