Task: Question Answering
Input (English): Problem: dexter and prexter are competing with each other in a friendly community competition in a pool of 50 m length and the race is for 1000 m . dexter crosses 50 m in 2 min and prexter in 3 min 15 sec . each time they meet / cross each other , they do handshake ' s . how many such handshake ' s will happen if they start from the same end at the same time ? 
Options: a ) 17 , b ) 18 , c ) 19 , d ) 20 , e ) 22
Output (English): c