How much time will a horse take to run around a square field of side 750 m if it runs at the speed of 25 km/h ?

432 sec. 

Distance = Speed × Time

To convert km/h into m/sec . 

 X km/h  ×  \(\frac{5}{18}\) = Y m/sec 

 25 km/h  ×  \(\frac{5}{18}\) =   25 × \(\frac{5}{18}\) m/sec 

750 = 25 × \(\frac{5}{18}\) × T

T = 18 × 6 = 108

Time for all 4 sides = 108 × 4 = 432 sec.