Solve for r : A=pir^2

—the graph shows how fast a strand of human hair grows. how many inches would the hair have grown in 5 months

If an athlete can bike 6 miles in 25 minutes, how many miles will he bike in an hour and half if he continues to bike at the same rate?

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?