*the* smart question

[VulcanRider]

Originally posted by mad=dog: Each year the elven court plants out seedlings of the sacred tree. According to tradition the seedlings is planted in 5 rows as symbol of the five elven archheroes with 4 seedlings in each row symbolising the elements. However this year the tree only produce 10 seedlings. The venerable elven king is distressed until he finally finds a way to fullfill the ceremony. How did he plant the seedlings?

In the shape of a 5-pointed star. Each of the 5 points and each place 2 lines cross is a plant. But I like ZFR's idea too...

[VulcanRider]

Four people need to cross a bridge at night. They have one flashlight for the four of them, but the bridge is only wide enough for two to cross at a time. Because it's so dark, anyone crossing the bridge must do so with the flashlight.

Allen can walk across in 1 minute. Betty takes 2 minutes; Cathy -- 5 minutes, and finally David needs a full 10 minutes to cross. Naturally, if two people are crossing the bridge, they move with the speed of the slower person.

What is the shortest amount of time it will take for all four to get to the other side?

[Sir Krustin]

19 minutes.

[Sir Goulum]

If Allen carried them, one by one, he would move at his speed(ok, take twice as long) and be finished in 4 (or 8 if in the bracket thing) minutes. [img]smile.gif[/img]

[VulcanRider]

Sir K, they can do better than that. Sir G, no.

[Seraph]

I get 17 minutes on the bridge problem, but I'm not sure its the quickest.
Allen and Betty cross (2 minutes)
Allen comes back (1 minute)
Cathy and David cross (10 minutes)
Betty comes back (2 minutes)
Allen and Betty cross (2 minutes)

[ZFR]

Originally posted by Callum: I still don't understand that children riddle? Is it just that 13 is the only number that has two sets of numbers that sum to it?

Yes that is the reason.

If it was any other combination which gives a unique sum, the person (who knew the number of windows) wouldve guessed it without needing the second clue.

Originally posted by VulcanRider: In the shape of a 5-pointed star. Each of the 5 points and each place 2 lines cross is a plant.

Yes, that would be right in the sense that we do get five rows of 4 seeds each,

But...

I just thought of something. Was the bit about eleven archheroes and four elements in the original riddle or was it something added by you? Because if the four seedling in each row represent the four elemnts then it is logical to assume that normally each row would contain 4 seedling each representing one different element.
Now in the star arrangement it is impossible to assign each seedling an element so that each row contains each of the four elements. Even the venerable elven king would be at a loss here .

[VulcanRider]

Originally posted by Seraph: I get 17 minutes on the bridge problem, but I'm not sure its the quickest. Allen and Betty cross (2 minutes) Allen comes back (1 minute) Cathy and David cross (10 minutes) Betty comes back (2 minutes) Allen and Betty cross (2 minutes)

You got it...

[mad=dog]

The five pointed star is the solution. The elven tale is meant for roleplaying atmosphere. Just as the plants do not need to belong exclusively to one row (hero) they don't need to belong exclusively to one element either to be sactified.

The bridge trick is to walk the slowest across simultaniously while a fast one is able to return the lamp. Even if the difference in travelling speed was less exagerated the solution would remain the same.

[ZFR]

You have six matchsticks of equal length. You are to arrange them in such a way to have 4 equilateral (all sides equal) triangles.

How to do that?