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

[EX Q]: Problem: solution a is 20 % salt and solution b is 70 % 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 ) 2 : 3 , d ) 4 : 6 , e ) 3 : 7
[EX A]: c

[EX Q]: Problem: the ratio of number of boys and girls in a school is 2 : 5 . if there are 490 students in the school , find the number of girls in the school ? 
Options: a ) 150 , b ) 350 , c ) 300 , d ) 370 , e ) 280
[EX A]: b

[EX Q]: Problem: a marketing firm determined that , of 200 households surveyed , 80 used neither brand e nor brand b soap , 60 used only brand e soap , and for every household that used both brands of soap , 3 used only brand b soap . how many of the 200 households surveyed used both brands of soap ? 
Options: a ) 15 , b ) 20 , c ) 30 , d ) 40 , e ) 45
[EX A]:
d