Here's how it works:
* Per hour: This means "for each hour" (e.g., 10 miles per hour).
* Per day: This means "for each day" (e.g., $50 per day).
* Per capita: This means "for each person" (e.g., the number of cars per capita in a country).
* Per cent: This means "out of one hundred" (e.g., 10 percent).
Essentially, "per" introduces a unit of measurement and indicates a rate or proportion related to that unit.