The hound jumps 4 times = the hare jumps 5 times: you can set the hound to jump 5 times and the hare to jump 4 times.
The hare jumps over the hound first 10 times =50 steps.
At the same time, the hound jumps 6×5 = 30 steps, and the rabbit jumps 7×4 = 28 steps.
So the hound jumps six times at a time, which can shorten the gap of two steps. 50/2=25。
The hound jumped 25X6= 150 times before catching up with the rabbit.