How many horses are at each stable if a man owns four stables and 13 horses?

* Divide the total horses by the number of stables: 13 horses / 4 stables = 3.25 horses per stable

* Since you can't have a fraction of a horse, you need to think about distribution: You could have 3 horses in each of 3 stables, and then 4 horses in the remaining stable.

Therefore, there isn't an even distribution of horses. You would have 3 stables with 3 horses each, and 1 stable with 4 horses.