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: by selling an article for $ 90 , a person gains $ 15 . what is the gain % ? 
Options: a ) 25 % , b ) 30 % , c ) 50 % , d ) 20 % , e ) 10 %

A: d
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Q: Problem: a car is purchased on hire - purchase . the cash price is $ 26 000 and the terms are a deposit of 10 % of the price , then the balance to be paid off over 60 equal monthly installments . interest is charged at 12 % p . a . what is the monthly installment ? 
Options: a ) $ 603 , b ) $ 624 , c ) $ 625 , d ) $ 626 , e ) $ 627

A: b
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Q: Problem: a trader bought a car at 15 % discount on its original price . he sold it at a 40 % increase on the price he bought it . what percent of profit did he make on the original price ? 
Options: a ) 119 , b ) 110 , c ) 112 , d ) 113 , e ) 115

A:
a
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