Task: Question Answering
Input (English): Problem: 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 ) 
Options: a ) 150 km , b ) 200 km , c ) 250 km , d ) 125 km , e ) 155 km
Output (English): a