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'.
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Question: Problem: in a class , if 50 % of the boys were girls , then there would be 50 % more girls than boys . what percentage of the overall class is girls ? 
Options: a ) 25 % , b ) 33.33 % , c ) 40 % , d ) 20 % , e ) 10 %

Answer: d


Question: Problem: at what rate percent per annum will the simple interest on a sum of money be 1 / 5 of the amount in 10 years ? 
Options: a ) 2 % , b ) 7 % , c ) 9 % , d ) 3 % , e ) 1 %

Answer: a


Question: Problem: a part of certain sum of money is invested at 9 % per annum and the rest at 12 % per annum , if the interest earned in each case for the same period is equal , then ratio of the sums invested is ? 
Options: a ) 4 : 7 , b ) 4 : 0 , c ) 4 : 3 , d ) 4 : 1 , e ) 4 : 2

Answer:
c