In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: how many times digit 5 is used while writing numbers from 100 to 1000 ? 
Options: a ) 648 , b ) 300 , c ) 252 , d ) 225 , e ) 290
Example Output: e

Example Input: Problem: marcella has 27 pairs of shoes . if she loses 9 individual shoes , what is the greatest number of matching pairs she could have left ? 
Options: a ) 22 , b ) 20 , c ) 19 , d ) 16 , e ) 15
Example Output: a

Example Input: Problem: a meal cost $ 32.50 and there was no tax . if the tip was more than 10 pc but less than 15 pc of the price , then the total amount paid should be : 
Options: a ) 40 - 42 , b ) 39 - 41 , c ) 38 - 40 , d ) 37 - 39 , e ) 36 - 37
Example Output:
e