The total number of students who participated in the survey are 100.Given to us The number of students who choose other as their favorite subject = 20 studentsMath = 30%English = 45%Let the total number of students in the survey be x.What is the percentage of students who choose other as their favorite subject?We know that percentage is always 100%, therefore,Total number of students in the survey = other + Math +English100% = other + 30% + 45%100% - 30% - 45% = otherother = 25%Thus, the percentage of students who choose another as their favorite subject is 25%.What is the total number of students who participated in the survey?We know that the number of students who choose English as their favorite subject in the surveys is 20, therefore,25% of the total number of students = 20Hence, the total number of students who participated in the survey is 100.