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 of equal lengths take 10 sec and 20 sec respectively to cross a telegraph post . if the length of each train be 120 m , in what time will they cross other travelling in opposite direction ? 
Options: a ) 16 sec , b ) 13 sec , c ) 17 sec , d ) 21 sec , e ) 23 sec

Output: b


Input: Consider Input: Problem: 28 machines can do a work in 10 days . how many machines are needed to complete the work in 40 days ? 
Options: a ) 10 , b ) 6 , c ) 4 , d ) 7 , e ) 5

Output: d


Input: Consider Input: Problem: a man traveled a total distance of 900 km . he traveled one - third of the whole trip by plane and the distance traveled by train is two - thirds of the distance traveled by bus . if he traveled by train , plane and bus , how many kilometers did he travel by bus ? 
Options: a ) 240 , b ) 280 , c ) 320 , d ) 360 , e ) 400


Output: d