Answer:
Percentage=33.33%
Explanation:
Total number of students=Number of 8th grader+others who went on trip
where;
Total number of students=60
Number of 8th graders=20
Others who went on trip=x
replacing;
60=20+x
x=(60-20)
x=40
Others who went on trip=x=40
Ratio of number of eighth graders to the number of everyone who went on the trip is;
Eighth graders who went=20 students
Everyone who went including the eighth graders=60
20/60==1/3
(1/3)×100=33.33%
Percentage=33.33%