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

[EX Q]: Problem: a pet store holds cats and dogs . if the difference between the number of cats and the number of dogs is 17 . what could be the ratio of cats to dogs in the pet store ? 
Options: a ) 1 : 3 , b ) 1 : 4 , c ) 1 : 5 , d ) 2 : 5 , e ) 68 : 85
[EX A]: e

[EX Q]: Problem: water consists of hydrogen and oxygen , and the approximate ratio , by mass , of hydrogen to oxygen is 2 : 16 . approximately how many grams of oxygen are there in 162 grams of water ? 
Options: a ) 16 , b ) 72 , c ) 112 , d ) 128 , e ) 144
[EX A]: e

[EX Q]: Problem: in a college , the ratio of the number of boys to girls is 6 : 5 . if there are 200 girls , the total number of students in the college is 
Options: a ) 440 , b ) 520 , c ) 620 , d ) 720 , e ) 820
[EX A]:
a