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: solve the equation for x : 8 x - 40 + 2 x = 5 + 10 - x 
Options: a ) 4 , b ) 10 , c ) 7 , d ) 5 , e ) 3

A: d
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Q: Problem: 2525 * 9 
Options: a ) 22725 , b ) 25675 , c ) 22655 , d ) 27575 , e ) none of these

A: a
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Q: Problem: if @ is a binary operation defined as the difference between an integer n and the product of n and 5 , then what is the largest positive integer n such that the outcome of the binary operation of n is less than 10 ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5

A:
b
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