Down stream distance = 16 miles \ \
\Up stream distance = 16 miles \ \
\Boat speed in still water = 6 mph \ \
\Total travelling time = 6 hours \ \
\Let x be the speed of the current (stream) \ \
\Down stream speed = Boat speed in still water + current speed = 6 + x \ \
\Up stream speed = Boat speed in still water - current speed = 6 - x \ \
\It takes 6 hours for a boater to travel 16 miles upstream and 16 miles back.Hence \ \
\Total travelling time = Upstream Time + Downstream Time \ \
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6(36 - x²) = 192 \ \
\216 - 6x² = 192 \ \
\6x² = 216 + 192 \ \
\x² = 408 \ \
\x = 20.199 \ \
\x = 20.2 \ \
\The Speed of the current is 20.2 mph \ \
\