Mrs. Carter is making snack packs for her class to eat on their field trip. She estimates that she will need 28 snack packs. The day of the field trip 8 students are absent and Mrs. Carter actually only needs 20 snack packs. Calculate Mrs. Carter’s percent error.

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.