Task: Question Answering
Input (English): Problem: two trains are moving in opposite directions at 60 km / hr and 90 km / hr . their lengths are 1.50 km and 1.25 km respectively . the time taken by the slower train to cross the faster train in seconds is ? 
Options: a ) 12 , b ) 77 , c ) 66 , d ) 99 , e ) 11
Output (English): c