<PRE><B>Question 763243</B>
At a river resort, you rent a motor boat for a sight seeing trip. You travel upstream at 9kph and return traveling downstream at 12mph. The whole trip lasts 3.5 hours. How far from the the resort did you travel before turning back?
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let x=how far traveled from resort before turning back
travel time=distance/speed
{{{x/9+x/12=3.5}}}
LCD:36
4x+3x=126
7x=126
x=18
how far traveled from resort before turning back=18 km</PRE>