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 moving in the same direction at 72 kmph and 36 kmph . the faster train crosses a man in the slower train in 20 seconds . find the length of the faster train ? 
Options: a ) 270 , b ) 277 , c ) 200 , d ) 257 , e ) 271

Output: c


Input: Consider Input: Problem: a and b can together finish a work in 40 days . they worked together for 10 days and then b left . after another 18 days , a finished the remaining work . in how many days a alone can finish the job ? 
Options: a ) 10 , b ) 24 , c ) 60 , d ) 30 , e ) 20

Output: b


Input: Consider Input: Problem: if 5 machines can produce 20 units in 10 hours , how long would it take 20 machines to produce 160 units ? 
Options: a ) 50 hours , b ) 40 hours , c ) 20 hours , d ) 12 hours , e ) 8 hours


Output: c