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'.

Ex Input:
Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 5 days , then the fraction of the work that is left is : 
Options: a ) 1 / 3 , b ) 7 / 12 , c ) 5 / 12 , d ) 2 / 3 , e ) 1 / 2

Ex Output:
c


Ex Input:
Problem: a train passes a station platform in 35 sec and a man standing on the platform in 20 sec . if the speed of the train is 54 km / hr . what is the length of the platform ? 
Options: a ) 228 , b ) 240 , c ) 225 , d ) 166 , e ) 1811

Ex Output:
c


Ex Input:
Problem: the consumption of diesel per hour of a bus varies directly as square of its speed . when the bus is travelling at 70 kmph its consumption is 1 litre per hour . if each litre costs $ 70 and other expenses per hous is $ 70 , then what would be the minimum expenditure required to cover a distance of 700 km ? 
Options: a ) 1000 , b ) 1500 , c ) 1240 , d ) 1630 , e ) 1400

Ex Output:

e