posted by Sam .
1. A bicycle racer covers a 75 mile training route to prepare for an upcoming race. If the racer could increase his speed by 5 mph, he would complete the same course in 3/4 of the time. Find his average rate of speed.
2. Nina drove for 6 hours at an average rate of 50 mph. During the first 5 hours he averaged 52 mph. What was her average speed during the last hour of driving?