In this task, you need to provide the correct option for a given problem from the provided options.
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Question: Problem: on a certain farm the ratio of horses to cows is 5 : 1 . if the farm were to sell 15 horses and buy 15 cows , the ratio of horses to cows would then be 17 : 7 . after the transaction , how many more horses than cows would the farm own ? 
Options: a ) 30 , b ) 40 , c ) 50 , d ) 60 , e ) 70

Answer: c


Question: Problem: the compound ratio of 1 : 2 , 3 : 2 and 4 : 5 ? 
Options: a ) 1 : 9 , b ) 1 : 7 , c ) 1 : 2 , d ) 3 : 5 , e ) 1 : 4

Answer: d


Question: Problem: in a circuit board factory , all circuit boards that pass a verification process are certified . every board that fails the verification process is indeed faulty , but 1 / 8 of those that pass are also faulty . approximately how many faulty circuit boards exist in a group of 3,200 circuit boards where 64 fail inspection ? 
Options: a ) 72 , b ) 192 , c ) 456 , d ) 256 , e ) 264

Answer:
c