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: john traveled 80 % of the way from yellow - town to green - fields by train at an average speed of 80 miles per hour . the rest of the way john traveled by car at an average speed of v miles per hour . if the average speed for the entire trip was 60 miles per hour , what is v in miles per hour ? 
Options: a ) 30 , b ) 40 , c ) 50 , d ) 55 , e ) 70

Output: a


Input: Consider Input: Problem: it takes 35 identical printing presses 12 hours to print 500,000 papers . how many hours would it take 30 of these printing presses to print 500,000 papers ? 
Options: a ) 14 , b ) 15 , c ) 16 , d ) 18 , e ) 20

Output: a


Input: Consider Input: Problem: a train 140 m long is running at 60 kmph . in how much time wiu it pass a platform 260 m long ? 
Options: a ) 21 sec , b ) 22 sec , c ) 23 sec , d ) 24 sec , e ) 26 sec


Output: d