Fun race
If that: there are 25 horses, five tracks, the game is not timed, ranking only get to select the top three fastest run requires a minimum of a few games.
solution:
1.25 horses divided into 5 groups a, b, c, d, e, five games. 5 according to the racing game game rankings are numbered 1,2,3,4,5, is obtained similar to the following ranking: a1> a2> a3> a4> a5.
2. for sixth abcde each first game, the game result is assumed that a1> b1> c1> d1> e1. Currently playing the game then the results are shown below:
3. Since only need to select the fastest 3 horses running on it, so the last two of each group will not be considered. group d and e at least than the group a1, b1, c1 slow, and therefore is no longer considered. Similarly, c2, c3 at least than a1, b1, c1 slow, b3 at least than a1, b1, b2 slow, does not consider. And a1 is already 25 horses in the fastest horse does not need to match.
4. 那么只剩下a2、a3、b1、b2、c1决出第二名和第三名即可（第七场）Therefore, the game can be derived seven top three.