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: a can do a work in 24 days and b can do it in 8 days . in how many days a and b can do the work ? 
Options: a ) 20 days , b ) 10 days , c ) 6 days , d ) 8 days , e ) 7 days

Output: c


Input: Consider Input: Problem: two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 21 seconds . the ratio of their speeds is ? 
Options: a ) 3 / 6 , b ) 3 / 2 , c ) 2 / 3 , d ) 3 / 5 , e ) 5 / 2

Output: c


Input: Consider Input: Problem: in a kilometer race , a beats b by 51 meters or 11 seconds . what time does a take to complete the race ? 
Options: a ) 22 , b ) 190 , c ) 277 , d ) 204 , e ) 208


Output: d