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'.
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Question: Problem: an electric pump can fill a tank in 6 hours . because of a leak in the tank , it took 12 hours to fill the tank . if the tank is full , how much time will the leak take to empty it ? 
Options: a ) 10 hours , b ) 12 hours , c ) 8 hours , d ) 5 hours , e ) 15 hours

Answer: b


Question: Problem: a swimmer can swim in still water at 4 km / h . if the speed of the water current is 2 km / h , how many hours will the swimmer take to swim against the current for 5 km ? 
Options: a ) 2.0 , b ) 2.5 , c ) 3.0 , d ) 3.5 , e ) 4.0

Answer: b


Question: Problem: a person can row at 9 kmph and still water . he takes 4 1 / 2 hours to row from a to b and back . what is the distance between a and b if the speed of the stream is 1 kmph ? 
Options: a ) 33 , b ) 77 , c ) 26 , d ) 28 , e ) 20

Answer:
e