1. For Halloween, Oliver wears a monocle that, its packaging claims, has a circumference of 18.84 centimeters. What is the monocle's radius? Use 3.14 for π.
2. After stepping into a room with unusual lighting, Monica's pupil has a diameter of 6 millimeters. What is the pupil's radius?
3. A round jar lid has a diameter of 6 centimeters. What is the lid's circumference? Use 3.14 for π.