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: 6 bells commence tolling together and toll at the intervals of 24 , 68 , 1012 seconds resp . in 60 minutes how many times they will toll together . 
Options: a ) 15 , b ) 16 , c ) 30 , d ) 31 , e ) none of these

Output: d


Input: Consider Input: Problem: noelle walks from point a to point b at an average speed of 6 kilometers per hour . at what speed , in kilometers per hour , must noelle walk from point b to point a so that her average speed for the entire trip is 7 kilometers per hour ? 
Options: a ) 6.75 , b ) 7 , c ) 7.25 , d ) 7.5 , e ) 8.4

Output: e


Input: Consider Input: Problem: a can do a job in 15 days and b in 30 days . if they work on it together for 4 days , then the fraction of the work that is left is ? 
Options: a ) 2 / 15 , b ) 3 / 5 , c ) 3 / 11 , d ) 1 / 12 , e ) 6 / 13


Output: b