So the best and correct answer is C because this is how you do it The surface area of the cone has formula

pi * radius * ( radius + sqrt ( height^2 + radius^2)) =
pi * radius^2 + pi * radius * sqrt( height^2 + radius^2)

However, this includes the base of the cone and the hats do NOT have
that. "The hats are shaped like a cone with NO BASE", says the 3rd sentence.

So the formula becomes pi * radius * sqrt( height^2 + radius^2)

diameter = 16
radius = 8
height = 9

The surface area of ONE of the hats is pi * 8 * sqrt( 9^2 + 8^2)
= pi * 8 * sqrt( 81+64)
= pi * 8 * sqrt(145)
302.63828053.....

21 of them is 21 * 302... = 6355.40689112841343251026086.....

6 0

3 years ago

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A recipe for bran muffins calls for 2 1/2 cups of bran flakes. The recipe yields 9 muffins. How much bran flakes should be used

kolbaska11 [484]

10/3 bran flakes can make a dozen muffins

A recipe requires 2 1/2 cups of bran flakes

The recipe can make 9 muffins

Let's calculate the amount of bran flakes it will take to make 1 muffin

5/2 = 9

x= 1

cross multiply

9x= 5/2

x= 5/18

A dozen is 12, the number of bran flakes to make a dozen can be calculated as follows

5/18= 1

y= 12

cross multiply

y= 5/18 × 12

y= 10/3

Hence it will take 10/3 to make a dozen muffins