A student earns R285 per week. She saved R75 per month. What percentage of her earnings does she save?

First, let's calculate how much she saves per week:
R75 per month / 4 weeks = R18.75 per week

Now, let's calculate the percentage of her earnings that she saves:
(R18.75 per week / R285 per week) x 100 = 6.58%

Therefore, the student saves approximately 6.58% of her earnings.

1. Find the number of weeks in a month.
There are 4 weeks in a month.

2. Calculate the student's monthly earnings.
Monthly earnings = Weekly earnings × Number of weeks in a month
Monthly earnings = R285 × 4
Monthly earnings = R1,140

3. Calculate the student's annual earnings.
Annual earnings = Monthly earnings × Number of months in a year
Annual earnings = R1,140 × 12
Annual earnings = R13,680

4. Calculate the student's annual savings.
Annual savings = Monthly savings × Number of months in a year
Annual savings = R75 × 12
Annual savings = R900

5. Calculate the percentage of earnings saved.
Percentage of earnings saved = (Annual savings / Annual earnings) × 100
Percentage of earnings saved = (R900 / R13,680) × 100
Percentage of earnings saved = 6.58%

Therefore, the student saves 6.58% of her earnings.