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: p can do a work in the same time in which q and r together can do it . if p and q work together , the work can be completed in 10 days . r alone needs 30 days to complete the same work . then q alone can do it in 
Options: a ) 10 , b ) 22 , c ) 25 , d ) 27 , e ) 30
Example Output: e

Example Input: Problem: to fill a tank , 20 buckets of water is required . how many buckets of water will be required to fill the same tank if the capacity of the bucket is reduced to one - fifth of its present ? 
Options: a ) 100 , b ) 200 , c ) 300 , d ) 400 , e ) 500
Example Output: a

Example Input: Problem: a ladder 25 m long reaches a window of building 20 m above the ground . then the distance of the foot of the ladder from the building is ? 
Options: a ) 35 m , b ) 45 m , c ) 30 m , d ) 15 m , e ) 25 m
Example Output:
d