Subject: mathqa
Question: a lady starts from p towards q and realizes that at a point r , if he walks 50 km further he will be at a point s , which is as far away from r as it is from q . what is the distance between p and q if the distance between p and r is half the distance from r to q ? ( assume that p , q , r and s are all on the same straight line )
Option: 
A: 150 km
B: 125 km
C: 155 km
D: 250 km
Answer: A