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'.

Q: Problem: a retailer bought a machine at a wholesale price of $ 108 and later on sold it after a 10 % discount of the retail price . if the retailer made a profit equivalent to 20 % of the whole price , what is the retail price of the machine ? 
Options: a ) 81 , b ) 100 , c ) 120 , d ) 135 , e ) 144

A: e
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Q: Problem: a car dealership has 40 cars on the lot , 15 % of which are silver . if the dealership receives a new shipment of 80 cars , 30 % of which are not silver , what percentage of total number of cars are silver ? 
Options: a ) 20 % , b ) 25 % , c ) 30 % , d ) 35 % , e ) 40 %

A: b
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Q: Problem: peter invested a certain sum of money in a simple interest bond whose value grew to $ 400 at the end of 4 years and to $ 500 at the end of another 2 years . what was the rate of interest in which he invested his sum ? 
Options: a ) 12 % , b ) 12.5 % , c ) 67 % , d ) 25 % , e ) 33 %

A:
d
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