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: 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: on a sum of money , the s . i . for 2 years is $ 600 , while the c . i . is $ 612 , the rate of interest being the same in both the cases . the rate of interest is ? 
Options: a ) 3 % , b ) 4 % , c ) 5 % , d ) 6 % , e ) 7 %

Answer: b


Question: Problem: by selling 100 pens , a trader gains the cost of 40 pens . find his gain percentage ? 
Options: a ) 40 % , b ) 50 % , c ) 60 % , d ) 70 % , e ) 30 %

Answer:
a