<PRE><B>Question 177537</B>
a motor boat took 3 hours to make a downstream trip with a 6 km/h current the return trip against the same current took 5 hours find the speed of the boat in still water.
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Downstream DATA:
time = 3 hr. ; rate = b+6 km/h ; distance = rt = 3(b+6) km
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Upstream DATA:
time = 5 hr. ; rate = b-6 km/h ; distance = rt = 5(b-6) km
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distance down = distance up
3(b+6) = 4(b-6)
3b+18 = 4b-24
b = 42 km/h (speed of the boat in still water)
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Cheers,
Stan H.</PRE>