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.
The probability would be 0.1971.
We will calculate a z-score for each end of this interval.
z = (X-μ)/σ
For the lower limit:
z = (1100-1050)/218 = 50/218 = 0.23
For the upper limit:
z = (1225-1050)/218 = 175/218 = 0.80
Using a z-table (http://www.z-table.com) we see that the area under the curve to the left of, less than, the lower limit is 0.5910. The area under the curve to the left of, less than, the upper limit is 0.7881. To find the area between them, we subtract:
0.7881 - 0.5910 = 0.1971
D.1/36 because it has 6 sides which can have an possible outcome of 36
Answer:
90 g of water should be added and he will make 900 g of solution.
Step-by-step explanation:
Let x g be the amount of salt Ilya add to 810g of water to make 10% solution. Then 810+x g is the amount of new solution. Thus,
810+x - 100%,
x - 10%.
Mathematically,

So 90 g of water should be added and he will make 810+90=900 g of solution.
3/8ths or 0.375 probability