Power is defined as rate of work done which means it is work done in 1 second of time
Now it is given that we have a horse that will give power 745.7 W
So it will do work of 745.7 J in 1 second of time
now if we wish to find the work done by horse in 0.55 s
so we can say
So it will do total work of 410.14 J in 0.55 s of time