As Olivia is driving her car on a long straight road, she spots Sophia cycling in the same direction mile in front of her. After she passes her, she can see her in her rear mirror until she is mile behind her. Olivia drives at a constant rate of 16 miles per hour, and Sophia cycles at a constant rate of 10 miles per hour. For how many minutes can Olivia see Sophia?
10
12
15
18
20