Task: Question Answering
Input (English): Problem: a and b go around a circular track of length 900 m on a cycle at speeds of 36 kmph and 54 kmph . after how much time will they meet for the first time at the starting point ? 
Options: a ) 120 sec , b ) 165 sec , c ) 186 sec , d ) 180 sec , e ) 168 sec
Output (English): d