## Welcome to BrainDen.com - Brain Teasers Forum

 Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account. As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends. Of course, you can also enjoy our collection of amazing optical illusions and cool math games. If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top. If you have a website, we would appreciate a little link to BrainDen. Thanks and enjoy the Den :-)
Guest Message by DevFuse

20 replies to this topic

### #11 lord

lord

Newbie

• Members
• 6 posts

Posted 04 March 2008 - 10:34 PM

i agree with eventhorizon completely.
• 0

### #12 brhan

brhan

• Members
• 466 posts

Posted 04 March 2008 - 10:36 PM

He would need to go 50 + x backwards to reach his original position.
50-x would be the distance the soldier would need to go _forward_ after delivering the letter to be where the leading soldier will be once the platoon moved 50m.

ya, I agree. My point was to stress the original and new locations are different. Thanx for the correction.
• 0

### #13 strykr1a0

strykr1a0

Junior Member

• Members
• 21 posts

Posted 04 March 2008 - 11:46 PM

He would need to go 50 + x backwards to reach his original position.
50-x would be the distance the soldier would need to go _forward_ after delivering the letter to be where the leading soldier will be once the platoon moved 50m.

Wait, is the answer a number? I thought it had to include some sort of variable -- I think the answer is

(100a^2)/(a^2 - b^2) where a is speed of soldier and b is the speed of the platoon

thank you
• 0

### #14 bonanova

bonanova

bonanova

• Moderator
• 5918 posts
• Gender:Male
• Location:New York

Posted 04 March 2008 - 11:53 PM

Spoiler for Looks like ...
Kudos to EventHorizon for getting it first.
• 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

### #15 strykr1a0

strykr1a0

Junior Member

• Members
• 21 posts

Posted 04 March 2008 - 11:59 PM

Spoiler for Looks like ...

sorry i found dumb, but how do we know the platoon went 50m when the soldier went back?

i thought that say the platoon barely moves and the soldier rans ultra fast (instanteous)
then the soldier ran 100 m

how are we coming out with a specific number? like 120.71 m?
• 0

### #16 bonanova

bonanova

bonanova

• Moderator
• 5918 posts
• Gender:Male
• Location:New York

Posted 05 March 2008 - 12:03 AM

sorry i found dumb, but how do we know the platoon went 50m when the soldier went back?

• 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

### #17 strykr1a0

strykr1a0

Junior Member

• Members
• 21 posts

Posted 05 March 2008 - 12:06 AM

LOL - paint me embarassed
• 0

### #18 thatguyagain

thatguyagain

Newbie

• Members
• 6 posts

Posted 05 March 2008 - 12:35 AM

I get how yall did the whole math part, but what if the total distance is looked at as positive for forward and negitive for the return

then the total distance traveled by the soldier would be the same as the rest of the platoon

50 m
• 0

### #19 brhan

brhan

• Members
• 466 posts

Posted 05 March 2008 - 04:36 PM

Wait, is the answer a number? I thought it had to include some sort of variable -- I think the answer is

Strykr,

ya, the answer is a real number.

sorry i found dumb, but how do we know the platoon went 50m when the soldier went back?

In my original post, I said while the soldier was delivering the letter, the whole platoon moved ahead by 50m.

There is a 50m long army platoon marching ahead. The last person in the platoon wants to give a letter to the first person leading the platoon. So while the platoon is marching he runs ahead, reaches the first person and hands over the letter to him and without stopping he runs and comes back to his original position. In the mean time the whole platoon has moved ahead by 50m. The question is how much distance did the last person cover during that time?

• 0

### #20 brhan

brhan

• Members
• 466 posts

Posted 05 March 2008 - 04:40 PM

I get how yall did the whole math part, but what if the total distance is looked at as positive for forward and negitive for the return

then the total distance traveled by the soldier would be the same as the rest of the platoon

50 m

Thatguyagain,

In that case, I would have used 'displacement' rather than distance. Don't you think so?
• 0

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users