Question

a new stable is being built for 25 horses if one stall can hold two hordes how many stalls should be built in the stable

Answer 1

There has to be 13 because 25 divided by 2 is 12.5 and if you round up the answer is 13.

Answer 2

  25 / 2  =  12.5 or  12 remainder 1 .

12 stalls is not enough, because 12 stalls can only hold 24 hordes.

13 stalls must be built.  12 of them will have 2 horses each,
and one of them will only have one horse.