NH> question #1:
NH>      What is the fewest number of races that need to be run to
NH> determine  which are the five fastest horses?

DM> 5.  Use a stopwatch, time the first place for each race, 
DM> see which one has the shortest time from the winners.

My mistrake was to state that timing devices were not allowed.

DM>Or, if no stopwatch allowed,

DM> 6 - take the five first-place winners from before, and put them 
against each other.

If the last place horse in one race were faster than 20 other horses, 
that doesn't work.

NH> consideration:

NH>      If the 25 horses are divided into (arbitrary) groups of 5,
NH> the  fastest horse in one group of 5 may be slower than any of
NH> the horses in  another group.

NH> question #2:

NH>      How would you show your progression in a matrix?

DM> Headings: Horse name, Time

I would also add columns for 1) distance behind the closest horse in the 
last race and 2) which horse it was that was the closest horse.

þ CMPQwk 1.42 999

--- Maximus/2 3.01