Answer:
4 : 5
Explanation:
We are told that 20 students saw the movie and 5 didn't, meaning there were in total 20 + 5 = 25 students; therefore, the ratio is
To simplify the ratio, we divide both the numerator and the denominator by 5. This gives
Hence, the ratio of the students who saw the movie to the total number is 4 : 5.