Instructions: 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: Problem: a and b can do a piece of work in 3 days , b and c in 4 days , c and a in 6 days . how long will c take to do it ? 
Options: a ) 33 , b ) 77 , c ) 24 , d ) 55 , e ) 71
Output:
c