Answer:
Explanation:
For example,
Solution: Finding a unit rate 
 If we divide 150 by 20, we get the unit rate for the ratio, 150 minutes for every 20 miles. 
150÷20=7.5 
So the runner is running 7.5 minutes per mile. We can multiply this unit rate by the number of miles: 
7.5 minutes mile × 6 miles = 45 minutes 
Thus it will take her 45 minutes to run 6 miles at this pace. 
If it takes her 45 minutes to run 6 miles, it will take her 45÷3=15 minutes to run 6÷3=2 miles at the same pace. 
If it takes her 15 minutes to run 2 miles, it will take her 4×15=60 minutes to run 4×2=8 miles at the same pace. Since 60 minutes is 1 hour, she is running at a speed of 8 miles per hour. 
We found her pace in minutes per miles in part (a).