Answer:
5.497787144 miles
Step-by-step explanation:
Remember that circumference of a circle can be calculated with:

r=radius
We also know that the radius is just a half of the diameter.
So, the radius of the track is (1/2)/2=1/4 miles
Now, use the circumference of a circle formula to find how much she runs in 1 lap.

Simplify

This is how much she runs in 1 lap.
Multiply by 3.5 for 3 and a half laps.

The answer is around 5.497787144 miles.
Assuming independence,
prob=P(late,early)+P(early,late)=(1/10)(2/5)+(2/5)(1/10)
Answer:

Step-by-step explanation:

Isolate d ; Divide both sides of the equation by 

Simplify

Note; Another formula for d(diameter) =

Answer:-2
Step-by-step explanation: