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Old 08-07-2007   #1
Jeremiah J
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Default Math ?: A boat takes 45 minutes to travel downstream 12 miles, but it takes 3

hours to make the return trip? determine the rate of the boat in still water. Determine the rate of the current. (hint: switch 45 minutes into hours). I had this math problem on a test in 1998, still don't know how to friggin figure it out .Gosh DANGET PIKI, you helped me solve this problem that's been in my stack of papers for 10 years almost. And to figure the speed of the boat was just friggin 10 miles per hour, it's humilliating garrrrrrrrrrrrAnd for anyone who could figure out the type of algebra this is, I mean there are linear inequates, consecutive integer, but what part of algebra is this. 10 points for whoever could figure this because there are soo many who answered.
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Old 08-07-2007   #2
KennyB
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OK, let the speed of the river be y (in miles per hour)You travel 12 miles in 45 minutes downstream, so you are making 16 miles per hour.Upstream, you make only 4 miles per hour.Your boat speed is a constant, call that xDownstream -- x + y = 16Upstream -- x - y = 4Add 'em up:2x = 20x = 10 miles per houry = 6 miles per hourQED
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Old 08-07-2007   #3
MathGoddess
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Let r = rate of the current and b=rate of the boat in still waterThenr+b = 12 miles/(3/4) hours or 16 mphr-b = 12/3 = 4 mphSo r = 4 + bthen 4+b+b = 162b = 12b = 6 = rate of boat in still waterr = 10 = downstream currentAnd Meg is a moron.
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