Travelling...
#920854
10/27/13 11:40 AM
10/27/13 11:40 AM
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Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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Art, Ben and Cam travel a 10 mile straight path.
They have a bike and a skateboard.
All 3 walk at 5 mph.
Anyone on bike goes 15 mph, on skateboard goes 6 mph.
They leave at same time, and arrive at end of path at same time.
What is shortest possible time?
NO TRICKS like double riding, carrying skateboard while biking...
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#920894
10/27/13 03:53 PM
10/27/13 03:53 PM
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Joined: Oct 2011
Posts: 3,440 47.79N, 122.24W
BobH
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Here's my answer. I hid it in case it is right and someone else wants to solve as well. I'm going to say 2 hours. One has to be walking at all times and anyone that will hand off the skateboard or bicycle has to be back alongside the walker to do it. So the last person can never be faster than as if he walked the whole way. As they all arrive together it must be at the walking pace, therefore 2 hours.
Bob As I've grown older, I've found that my memory is not as good as I used to think it was.
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Re: Travelling...
[Re: CanukDenis]
#920935
10/27/13 08:52 PM
10/27/13 08:52 PM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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No, that wouldn't be a trick, since there is nothing in the wording that prevents a "rest".
However, can be done in less than 100 minutes, plus (in my solution) no one takes a rest.
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#920984
10/28/13 08:10 AM
10/28/13 08:10 AM
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Joined: Jul 2002
Posts: 29,026 Unionville
manxman
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Not sure if it is solid reasoning but..... 1. walking the 10 miles takes 2 hours 2. biking the 10 miles takes 2/3 hours 3. skateboarding the 10 miles takes 5/3 hours Since all three people must be doing one of the three at all times then the total times divided by 3 should be how long it takes for everything to get there. 2+2/3 + 5/3 = 13/3 13/3 /3 =13/9
Sometimes lost is where you need to be. Just because you don't know your direction doesn't mean you don't have one.
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Re: Travelling...
[Re: CanukDenis]
#920990
10/28/13 08:28 AM
10/28/13 08:28 AM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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Good thinking, but will not work in practice.
Say Art starts off with bike: he is always ahead of Ben and Cam while on the bike; so when he gets off, he must leave the bike and start walking.
So the bike will not be used for a while, until Ben or Cam get to it...
Ok?
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#921021
10/28/13 12:58 PM
10/28/13 12:58 PM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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HINT: 2 of the guys arrive at the 10mile point walking, while the other arrives on the bike. So the skateboard is not used all the way.
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#921193
10/29/13 02:16 PM
10/29/13 02:16 PM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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Hint#2: After the bike is left by whoever uses it first, it remains unused for 32 minutes before being used again.
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#921354
10/30/13 01:22 PM
10/30/13 01:22 PM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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Hint#3: the guy who starts off using the skateboard leaves it after a few miles; not used after.
I'm a man of few words, BUT I use 'em often!!
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Re: Travelling...
[Re: CanukDenis]
#922019
11/02/13 11:11 AM
11/02/13 11:11 AM
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Joined: Nov 2000
Posts: 18,719 Ottawa Ontario Canada
CanukDenis
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In case I forget... Assume Art starts on bike, Ben by walking, Cam on skate board
Art: 4 miles on bike[1], 6 miles walking Ben: 4 miles walking, 4 miles on bike[2], 2 miles walking Cam: 8 miles on skateboard[3], 2 miles on bike
[1]: bike left for 32 minutes [2]: bike left for 16 minutes [3]: skateboard remains behind
Art: 16 + 72 = 88 Ben: 48 + 16 + 24 = 88 Cam: 80 + 8 = 88
I'm a man of few words, BUT I use 'em often!!
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