Final answer:
Divide the total number of students by the sum of the ratio parts to find the value of one part, then multiply by the number of parts for sandals to find that 25 students are wearing sandals.
Step-by-step explanation:
The student has asked to calculate how many of them are wearing sandals when the ratio of students wearing sandals to those wearing sneakers is 5 : 1, and there are 30 students in total.
Since the ratio of sandals to sneakers is 5:1, we can imagine 6 parts in total because 5 parts are for sandals and 1 part is for sneakers. Given 30 students, each part would represent 30 / 6 = 5 students.
Therefore, since there are 5 parts for sandals, there would be 5 parts x 5 students/part = 25 students wearing sandals.