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: solution x is 10 percent alcohol by volume , and solution y is 30 percent alcohol by volume . how many milliliters of solution y must be added to 150 milliliters of solution x to create a solution that is 25 percent alcohol by volume ? 
Options: a ) 250 / 3 , b ) 500 / 3 , c ) 400 , d ) 450 , e ) 600

A: d
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Q: Problem: the unit digit in the product ( 784 x 618 x 917 x 463 ) is : 
Options: a ) 5 , b ) 9 , c ) 16 , d ) 2 , e ) 42

A: d
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Q: Problem: if x , y , and z are positive real numbers such that x + y - z = 62 , y - z + x = 82 , and z - x + y = 100 , then find the x + y + z value ? 
Options: a ) 80 , b ) 91 , c ) 62 , d ) 74 , e ) 82

A:
e
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