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: a man walking at a rate of 15 km / hr crosses a bridge in 20 minutes . the length of the bridge is ?
Options: a ) 1250 m , b ) 1110 m , c ) 950 m , d ) 1000 m , e ) 1300 m
[A]: d

[Q]: Problem: on a certain transatlantic crossing , 40 percent of a ship ' s passengers held round - trip tickets and also took their cars abroad the ship . if 20 percent of the passengers with round - trip tickets did not take their cars abroad the ship , what percent of the ship ' s passengers held round - trip tickets ?
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 80 %
[A]: c

[Q]: Problem: a store reduced the price of all items in the store by 15 % on the first day and by another 10 % on the second day . the price of items on the second day was what percent of the price before the first reduction took place ?
Options: a ) 76.5 , b ) 80.9 , c ) 81.0 , d ) 81.1 , e ) 81.9
[A]:
a