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'.

Example Input: Problem: kathleen can paint a room in 2 hours , and anthony can paint an identical room in 7 hours . how many hours would it take kathleen and anthony to paint both rooms if they work together at their respective rates ? 
Options: a ) 28 / 9 , b ) 4 / 3 , c ) 15 / 8 , d ) 9 / 4 , e ) 15 / 4
Example Output: a

Example Input: Problem: if 36 men can do a piece of work in 5 hours , in how many hours will 15 men do it ? 
Options: a ) 12 , b ) 38 , c ) 60 , d ) 88 , e ) 72
Example Output: a

Example Input: Problem: 33 cubic centimetres of silver is drawn into a wire 1 mm in diameter . the length of the wire in metres will be : 
Options: a ) 84 m , b ) 88 m , c ) 42 m , d ) 137 m , e ) none
Example Output:
c