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: the speed of a car is 60 km in the first hour and 30 km in the second hour . what is the average speed of the car ? 
Options: a ) 45 kmph , b ) 65 kmph , c ) 75 kmph , d ) 85 kmph , e ) 90 kmph

Output: a


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: in a 100 m race , sam beats john by 4 seconds . on the contrary , if sam allowed john to start 24 m ahead of sam , then sam and john reach the finishing point at the same time . how long does sam take to run the 100 m race ? 
Options: a ) 4 seconds , b ) 25 seconds , c ) 19 seconds , d ) 21 seconds , e ) 6.25 seconds


Output: c