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: find the compound interest on $ 800 for 1 year at 10 % p . a . if ci is component yearly ? 
Options: a ) $ 40 , b ) $ 400 , c ) $ 840 , d ) $ 800 , e ) $ 80
[EX A]: a

[EX Q]: Problem: from the sale of sleeping bags , a retailer made a gross profit of 16 % of the wholesale cost . if each sleeping bag was sold for $ 28 , what was the wholesale cost per bag ? 
Options: a ) 3.0 , b ) 3.36 , c ) 24.13 , d ) 25.0 , e ) 31.36
[EX A]: c

[EX Q]: Problem: a customer went to a shop and paid a total of $ 30 , out of which 90 cents was for sales tax on taxable purchases . if the tax rate was 6 % , then what was the cost of the tax free items ? 
Options: a ) $ 12.70 , b ) $ 13.20 , c ) $ 14.10 , d ) $ 15.60 , e ) $ 16.80
[EX A]:
c