The ratio of students who study french to students who do not study the french is  :
 :  .
.
Step-by-step explanation:
      The given is,
             50% of students are interested to study a language.
             But 2 students only study french.
Step:1
            Assume the number students in school are 100 in equal to the percentage.
            So, 50% of students are interested to study a language, so we assume 50 students are interested to study language.
           T= 50
            where, T = 50 % of students (50 students)
Step:2
            Let, X - Students interested to study french
                   Y - Students are not interested to study french
Step:3
            Ratio of students interested to study french
                        = 
           From given, 
                        = 
                        = 
              Ratio of students interred to french is 
Step:4
            Ration of students do not interested to french is 
                       = 
                       = 
                       = 
Result: 
            In a 50% of students in a school the ratio of students who study french to students who do not study the french is  :
 : 