On Mar 14, 2013, at 12:29 PM, Joe Niederberger <email@example.com> wrote:
> I wouldn't call it a constraint, but its natural in this context to look for the least number of races needed.
Call it a constraint or a hint, but generally problems like this (and the coin problem) include the goal. If you are not going to supply the "7" then why even supply the "25" and "5". Just say "Given X bicycles and Y riders find the minimum number of races to determine Z places. Or, given the 7 bridge problem, instead of the constraint of crossing each bridge once (there is that 7 again) just ask what is the minimum number of crossings.
If we look again at how (poorly) the problem was originally stated...
"There are 25 bicyclists and just 5 bicycles. Of all these we need to find best 3 cyclists. How many races should be held to determine top three winners and why?"
I still say that Elander's answer of "5" works best.
Reminds me of the physics problem "Given an altimeter, find the height of a building."