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

Problem: the present ratio of students to teachers at a certain school is 30 to 1 . if the student enrollment were to increase by 50 students and the number of teachers were to increase by 5 , the ratio of students to teachers would then be 25 to 1 . what is the present number of teachers ? 
Options: a ) 5 , b ) 8 , c ) 10 , d ) 12 , e ) 15
e

Problem: in a graduating class of 232 students , 144 took geometry and 119 took biology . what is the difference between the greatest possible number p and the smallest possible number of students that could have taken both geometry and biology ? 
Options: a ) 144 , b ) 119 , c ) 113 , d ) 88 , e ) 31
d

Problem: a jar contains a mixture of ab in the ratio 3 : 2 . when 10 l of mixture is replaced with liquid b , ratio becomes 2 : 3 . how many liters of liquid a was present in mixture initially . 
Options: a ) 18 , b ) 15 , c ) 16 , d ) 20 , e ) 25

a