The volume of a cone uses the following formula:

Our diameter is 20 feet, so divide this by 2 to find the radius:

We now have all of our values need to fill in the formula. Plug in these values:




The volume of the cone is
1780 cubic feet.
Divide total miles by miles per gallon:
364 miles / 20 miles per gallon = 18.2 gallons
This is Pythagorean's Theorem, with one leg being 10 and the hypotenuse being 16. Using those values in the theorem looks like this:

and

and

so

Take the square root of both sides to find that b = 12.5
She made an error in the STEP 1
she shouldnt multiply the numbers
−3/4+(1/10÷2/5)
parenthesis first
1/10 divided by 2/5
copy dot flip
1/10 * 5/2
5/20
1/4
−3/4+(1/10÷2/5)
-3/4 + 1/4
-2/4
divide top and bottom by 2
-1/2