How to know the difference between, irrational, rational, whole, ext

What is the approximate circumference of the circle shown below?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

The total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?