In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: jar a has 6 % more marbles than jar b . what percent of marbles from jar a need to be moved into jar b so that both jars have equal marbles ? 
Options: a ) 2.8 % , b ) 3.0 % , c ) 3.2 % , d ) 3.4 % , e ) 3.6 %

A: a
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Q: Problem: a man can row his boat with the stream at 6 km / h and against the stream in 3 km / h . the man ' s rate is ? 
Options: a ) 1.5 kmph , b ) 3 kmph , c ) 8 kmph , d ) 7 kmph , e ) 5 kmph

A: a
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Q: Problem: in a certain pond , 80 fish were caught , tagged , and returned to the pond . a few days later , 80 fish were caught again , of which 2 were found to have been tagged . if the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond , what ` s the approximate number of fish in the pond ? 
Options: a ) 400 , b ) 625 , c ) 1250 , d ) 3200 , e ) 10 000

A:
d
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