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: two trains a and b starting from two points and travelling in opposite directions , reach their destinations 9 hours and 4 hours respectively after meeting each other . if the train a travels at 100 kmph , find the rate at which the train b runs . 
Options: a ) 40 , b ) 60 , c ) 150 , d ) 80 , e ) 100

Output: c


Input: Consider Input: Problem: calculate the speed of a boat in still water ( in km / hr ) if in one hour , the boat goes 10 km / hr downstream and 4 km / hr upstream . 
Options: a ) 7 kmph , b ) 8 kmph , c ) 9 kmph , d ) 7 kmph , e ) 6 kmph

Output: a


Input: Consider Input: Problem: the l . c . m of two numbers is 2310 and their h . c . f is 30 . if one number is 210 the other is 
Options: a ) 330 , b ) 300 , c ) 270 , d ) 250 , e ) 350


Output: a