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'.
--------
Question: 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

Answer: c

Question: Problem: john makes $ 50 a week from his job . he earns a raise and now makes $ 80 a week . what is the % increase ?
Options: a ) 16 % , b ) 16.66 % , c ) 17.9 % , d ) 18.12 % , e ) 60 %

Answer: e

Question: Problem: an error 2 % in excess is made while measuring the side of a square . the percentage of error in the calculated area of the square is
Options: a ) 4.04 % , b ) 4.00 % , c ) 4.14 % , d ) 5.04 % , e ) none

Answer:
a