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 gambler has won 40 % of his 30 poker games for the week so far . if , all of a sudden , his luck changes and he begins winning 80 % of the time , how many more games must he play to end up winning 60 % of all his games for the week ? 
Options: a ) 20 , b ) 25 , c ) 30 , d ) 35 , e ) 40

A: c
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Q: Problem: if it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 900 responses are needed , what is the minimum number of questionnaires that should be mailed ? 
Options: a ) 1300 , b ) 1350 , c ) 1400 , d ) 1450 , e ) 1500

A: e
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Q: Problem: if the compound interest on a certain sum of money for 6 years at 10 % per annum be rs . 993 , what would be the simple interest ? 
Options: a ) rs . 880 , b ) rs . 890 , c ) rs . 1800 , d ) rs . 900 , e ) none

A:
c
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