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: if 20 typists can type 48 letters in 20 minutes , then how many letters will 30 typists working at the same rate complete in 1 hour ?
Options: a ) 63 , b ) 72 , c ) 144 , d ) 216 , e ) 400

Output: d

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: a brick measures 20 cm * 10 cm * 7.5 cm how many bricks will be required for a wall 29 m * 2 m * 0.75 m ?
Options: a ) 29000 , b ) 27908 , c ) 78902 , d ) 25000 , e ) 27991
Output: a