Answer:
39 percent is increase in mileage.
Thus, the correct option is B. 39%.
Step-by-step explanation:
Given:
A runner increased her distance from 9 miles to 12.5 miles a week.
Now, to find percent increase in mileage.
Previous mileage = 9 miles.
Present mileage = 12.5 miles.
Mileage increase = 12.5 - 9 = 3.5 miles.
Now, to get the percent increase in mileage:
[tex]\frac{Mileage\ increased}{previous\ mileage} \times 100[/tex]
[tex]=\frac{3.5}{9} \times 100[/tex]
[tex]=\frac{350}{9}[/tex]
[tex]=38.88\%.[/tex]
Approximately the percent increase = 39%.
Therefore, 39% is increase in mileage.
Thus, the correct option is B. 39%.
