Roger and Kelly are going on a road trip. If Roger drives at his normal rate of speed for the first 4 hours, then Kelly can drive the remaining distance in 4 more hours. If, however, Roger drives 75% faster than normal for 4 hours, Kelly can drive the remaining distance at her regular rate of speed in 2 hours. In the table below, choose a normal rate of speed for Roger and a normal rate of speed for Kelly that are consistent with the information above.

Roger No
50 miles/hour
55 miles/hour
60 miles/hour
65 miles/hour
70 miles/hour
75 miles/hour