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: a water tank is four - fifths full . pipe a can fill a tank in 10 minutes and pipe b can empty it in 6 minutes . if both the pipes are open , how many minutes will it take to empty or fill the tank completely ? 
Options: a ) 6 , b ) 9 , c ) 10 , d ) 12 , e ) 15
d

Problem: a 250 meter long train crosses a man standing on the platform in 12 sec . what is the speed of the train ? 
Options: a ) 228 , b ) 108 , c ) 1266 , d ) 75 , e ) 211
d

Problem: a 160 meter long train crosses a man standing on the platform in 12 sec . what is the speed of the train ? 
Options: a ) 48 kmph , b ) 54 kmph , c ) 92 kmph , d ) 86 kmph , e ) 76 kmph

a