A real Brain Hopper

Sean · Guest

You are a General at the rear of an army that is 5 miles long. The army is marching at a rate of 10 miles per hour. You decide to dispatch a courier to deliver a message to the General at the front of the army. The courier is told to drop the message and return immediately. Assuming that he galloped his horse at a rate of 20 miles per hour, what distance had he travelled when he returned?

Guest · Posted: Sat Jan 07, 2006 5:01 am Post subject:

my GUESS just a guess is 14

Guest · Posted: Sat Jan 07, 2006 7:01 am Post subject:

i think its like 13 1/3 miles

BlueRose713 · New Member Joined: 06 Jun 2006 Posts: 17

Wouldn't it be, like, 5 miles because the length of the army doesn't change but the courier is just traveling faster than the army?

(if this sounds dumb, well, i seriously dislike math, and thus did not care to understand it and incorporate in my mind in class...) Laughing

deryk · Guy Who Comes A Lot Joined: 19 May 2006 Posts: 159

i think its 12 miles.
it would take him 30 min to get to the front of the army, and going at 20 mph that would mean he travled 10 miles. on the way back going 20 mph one way and the army going 10 mph the other he is travleling a difference of 30 mph, and it would take 6 min to travle 5 miles at 30 mph. 6 min at 20mph would make 2 miles of actual travel. 10 miles on the way there in 30 min. + 2 miles on the way back in 6 min. making a total of 12 miles in 36 min.

deryk · Guy Who Comes A Lot Joined: 19 May 2006 Posts: 159

maybe this will help visualize Confused

--------------------------you--------------->20

---------------army-------------------------->10
difference of 10 mph, it takes 30 min or .5 hours to travel 5 miles at 10mph

--------------------you---------------------->-20

----------------------army------------------->10
difference of 30 mph, it takes 6 min or .1 hours to travel 5 miles at 30 mph

then plug it in, .5hours*20mph + .1hours*20mph=12 miles

Unclever title · Posted: Fri Jun 09, 2006 11:28 am Post subject:

No offense, but I wouldn't call this a riddle. It's a math problem! Don't get me wrong, there are thousands of math based riddles out there, and though I don't really like them, I consider them to be riddles. This is cut and dry enough to be found in a math homework sheet. Again, no offense intended, I just call them as I see them.

It's not neccessarily the easiest math problem becaue it involes a longer trip forward than back, but it is still a math problem.

BlueRose713 · New Member Joined: 06 Jun 2006 Posts: 17

[quote="Unclever title"]No offense, but I wouldn't call this a riddle. It's a math problem! Don't get me wrong, there are thousands of math based riddles out there, and though I don't really like them, I consider them to be riddles. This is cut and dry enough to be found in a math homework sheet. Again, no offense intended, I just call them as I see them.

It's not neccessarily the easiest math problem becaue it involes a longer trip forward than back, but it is still a math problem.[/quote]

Thank You! Very Happy

Riddleman · Site Admin Joined: 18 May 2005 Posts: 595

I dont like math riddles