In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Input: Consider Input: Problem: two trains are approaching each other at 60 mph each . the length of each train is 1 / 6 miles . when the two locomotives ( engines ) meet , how many seconds will it take for them to pass each other completely ? 
Options: a ) 8 sec , b ) 11 sec , c ) 12 sec , d ) 10 sec , e ) 15 sec

Output: d


Input: Consider Input: Problem: a tank can be filled by two pipes a and b in 60 minutes and 40 minutes respectively . how many minutes will it take to fill the tank from empty state if b is used for the first half time and then a and b fill it together for the other half . 
Options: a ) 15 mins , b ) 20 mins , c ) 25 mins , d ) 30 mins , e ) 35 mins

Output: d


Input: Consider Input: Problem: a pipe can empty 2 / 3 rd of a cistern in 12 mins . in 8 mins , what part of the cistern will be empty ? 
Options: a ) 2 / 3 , b ) 2 / 5 , c ) 4 / 9 , d ) 5 / 7 , e ) 4 / 11


Output: c