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'.

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']
b

Problem: the length of the bridge , which a train 130 metres long and travelling at 108 km / hr can cross in 30 seconds , is : 
Options: a ) 200 m , b ) 225 m , c ) 245 m , d ) 170 m , e ) 240 m
d

Problem: an engine moves at the speed of 60 kmph without any coaches attached to it . speed of the train reduces at the rate that varies directly as the square root of the number of coaches attached . when 4 coaches are attached speed decreases to 48 kmph . what will be the speed of train when 36 coaches are attached . 
Options: a ) 24 , b ) 28 , c ) 20 , d ) 32 , e ) 40

a