In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: drum x is 1 / 2 full of oil and drum y , which has twice the capacity of drum x , is 1 / 5 full of oil . if all of the oil in drum x is poured into drum y , then drum y will be filled to what capacity ? 
Options: a ) 3 / 10 , b ) 7 / 10 , c ) 9 / 10 , d ) 9 / 20 , e ) 13 / 20

A: d
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Q: Problem: the average of 13 numbers is 60 . average of the first 7 of them is 57 and that of the last 7 is 61 . find the 8 th number ? 
Options: a ) 43 , b ) 30 , c ) 35 , d ) 45 , e ) 50

A: a
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Q: Problem: a factory producing tennis balls stores them in either big boxes , 25 balls per box , or small boxes , 20 balls per box . if 104 freshly manufactured balls are to be stored , what is the least number of balls that can be left unboxed ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5

A:
e
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