[net.math] Spider and the Fly

john@hp-pcd.UUCP (09/09/83)

#N:hp-pcd:6100002:000:671
hp-pcd!john    Sep  8 19:03:00 1983

Heres a interesting puzzle that some of you may enjoy:


     A spider and a fly are both in a rectangular room with 30 foot long side
walls,12 foot wide end walls and a 12 foot high ceiling. The spider is on a 
end wall exactly 6 feet from either side wall and 1 foot down from the ceiling.
The fly is on the other end wall exactly 6 feet from either side wall and 1 
foot up from the floor. The spider can travel over floor,wall or ceiling with 
equal ease and the fly does not move irregardless of the consequences. What
is the shortest distance that the spider has to travel to catch the fly?



I'll post the answer at a later date.


John Eaton

hplabs!hp-pcd!john

toma@fluke.UUCP (Tom Anderson) (09/13/83)

The answer is forty feet.  If you unfold the room these hapless 
insects reside in like this (please excuse the poor draftmanship):

	
		_______________________________
		|                             |
		|                             |
		|  _ _ _ _ _ _ _ _ _ _ _ _ _  |______
		|                                   |
		|                              S    |
		|  _ _ _ _ _ _ _ _ _ _ _ _ _  ______|
		|                             |
		|                             |
	  ______|  _ _ _ _ _ _ _ _ _ _ _ _ _  |
	  |                                   |
	  |    F                              |
	  |___________________________________|


    Should be pretty obvious to any reasonable spider.


				Tom Anderson
				John Fluke Mfg.