Hey, I will try to answer, so here it goes:

Hare is 50 leaps of her own before hound so lets take her initial position 50*1.75= 87.5 Meters

Now it is said that Hare takes 4 leaps and the hound takes 3 therefore 87.5 + 4(1.75)x=3(2.75)x

solve the above equation and you should get x=87.5/1.25