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'.

Problem: in an office , 20 percent of the workers have at least 5 years of service , and a total of 16 workers have at least 10 years of service . if 90 percent of the workers have fewer than 10 years of service , how many of the workers have at least 5 but fewer than 10 years of service ? 
Options: a ) 32 , b ) 64 , c ) 50 , d ) 144 , e ) 160
a

Problem: there are 200 employees in a room . 99 % are managers . how many managers must leave the room to bring down the percentage of managers to 98 % ? 
Options: a ) 150 , b ) 100 , c ) 99 , d ) 50 , e ) 25
b

Problem: in an election between two candidates , one got 55 % of the total valid votes , 20 % of the votes were invalid . if the total number of votes was 6000 , the number of valid votes that the other candidate got , was : 
Options: a ) 2800 , b ) 2700 , c ) 2160 , d ) 2200 , e ) 2300

c