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'.

[EX Q]: Problem: sam invested $ 1000 @ 20 % per annum for one year . if the interest is compounded half yearly , then the amount received by sam at the end of the year will be ? 
Options: a ) $ 1542 , b ) $ 1145 , c ) $ 1210 , d ) $ 1642 , e ) $ 1020
[EX A]: c

[EX Q]: Problem: if the cost price of 55 articles is equal to the selling price of 50 articles , then what is the percent profit ? 
Options: a ) 5 % , b ) 10 % , c ) 15 % , d ) 20 % , e ) 25 %
[EX A]: b

[EX Q]: Problem: population of a city in 20004 was 1000000 . if in 2005 there isan increment of 15 % , in 2006 there is a decrement of 35 % and in 2007 there is an increment of 45 % , then find the population of city at theend of the year 2007 
Options: a ) 2456789 , b ) 3458009 , c ) 3890043 , d ) 3455048 , e ) 1083875
[EX A]:
e