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'.
--------
Question: Problem: if z is not equal to zero , and z = 6 zs − 9 s 2 − − − − − − − − √ z = 6 zs − 9 s 2 , then z equals : 
Options: a ) s , b ) 3 s , c ) 4 s , d ) - 3 s , e ) - 4 s

Answer: b


Question: Problem: the unit digit in the product ( 891 * 781 * 912 * 463 ) is : 
Options: a ) 2 , b ) 5 , c ) 6 , d ) 8 , e ) 10

Answer: c


Question: Problem: a recipe requires 2 1 / 2 ( mixed number ) cups of flour 2 3 / 4 ( mixed number ) cups of sugar and 1 1 / 3 ( mixed number ) cups of milk to make one cake . victor has 15 cups if flour , 16 cups of sugar and 8 cups of milk . what is the greatest number of cakes john can make using this recipe ? 
Options: a ) 5 , b ) 6 , c ) 7 , d ) 8 , e ) 9

Answer:
a