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 Q]: Problem: two diagonals of a rhombus are 72 cm and 30 cm respectively . what is its perimeter ? 
Options: ['a ) 136 cm', 'b ) 156 cm', 'c ) 144 cm', 'd ) 121 cm', 'e ) 126 cm']
[EX A]: b

[EX Q]: Problem: a train passes a station platform in 60 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 ) 615 m , b ) 420 m , c ) 168 m , d ) 197 m , e ) 691 m
[EX A]: b

[EX Q]: Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 3 days , then the fraction of the work that is left is 
Options: a ) 8 / 17 , b ) 7 / 15 , c ) 3 / 15 , d ) 8 / 15 , e ) 13 / 20
[EX A]:
e