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'.

[Q]: Problem: a man sitting in a train which is travelling at 64 kmph observes that a goods train travelling in a opposite direction , takes 18 seconds to pass him . if the goods train is 420 m long , find its speed . 
Options: a ) 32 , b ) 15 , c ) 18 , d ) 20 , e ) 25
[A]: d


[Q]: 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
[A]: a


[Q]: Problem: the speed of a boat in still water is 15 km / hr and the rate of current is 3 km / hr the distance travelled downstream in 12 minutes is : 
Options: a ) 2 km , b ) 2.6 km , c ) 3.6 km , d ) 4 km , e ) none
[A]:
c