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The total cost without the discount is given by:
$
Then, to find the discounted amount, we make the following rule of three:
10 $ ------------------> 100%
x ----------------------> 20%
From here, we clear the value of x.
We have then:

Then, the cost of the Strawberries with the discount is:
$
Answer:
Kate pays for the strawberries about $ 8.
The shape that is generated is a Cone.
A triangle, when rotated about one of it's side will generate a solid in a form of a Cone. The cone could be a hollow one or a solid filled one, depending on the properties of the triangle being rotated.