In this task, you need to provide the correct option for a given problem from the provided options.

Input: Consider Input: Problem: solution a is 30 % salt and solution b is 80 % salt . if you have 30 ounces of solution a and 60 ounces of solution b , in what ratio could you mix solution a with solution b to produce 50 ounces of a 50 % salt solution ? 
Options: a ) 6 : 4 , b ) 6 : 14 , c ) 4 : 4 , d ) 4 : 6 , e ) 3 : 2

Output: e


Input: Consider Input: Problem: the probability that a computer company will get a computer hardware contract is 4 / 5 and the probability that it will not get a software contract is 3 / 5 . if the probability of getting at least one contract is 9 / 10 , what is the probability that it will get both the contracts ? 
Options: a ) 1 / 8 , b ) 2 / 9 , c ) 3 / 10 , d ) 4 / 11 , e ) 5 / 12

Output: c


Input: Consider Input: Problem: how many of the positive factors of 36 are not factors of 72 
Options: a ) 0 , b ) 3 , c ) 4 , d ) 5 , e ) 1


Output: a