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: mahesh marks an article 15 % above the cost price of rs . 540 . what must be his discount percentage if he sells it at rs . 460 ? 
Options: a ) 18 % , b ) 21 % , c ) 25.9 % , d ) 19 % , e ) none of these

A: c
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Q: Problem: what percent of 120 are 90 ? 
Options: a ) 25 % , b ) 50 % , c ) 75 % , d ) 33 % , e ) 30 %

A: c
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Q: Problem: a glass was filled with 40 ounces of water , and 0.01 ounce of the water evaporated each day during a 20 - day period . what percent of the original amount of water evaporated during this period ? 
Options: a ) 0.005 % , b ) 0.02 % , c ) 0.5 % , d ) 5 % , e ) 20 %

A:
c
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