Task: Question Answering
Input (English): Problem: the distance between two cities a and b is 600 km . a train starts from a at 8 a . m . and travel towards b at 60 km / hr . another train starts from b at 9 a . m and travels towards a at 75 km / hr . at what time do they meet ? 
Options: a ) 09 am , b ) 07 am , c ) 01 pm , d ) 05 pm , e ) 03 pm
Output (English): c