Question

the pie factory sells an apple pie with a diameter of 16 in. for $10.99. What's the approximate cost per square inch of surface area of the pie? Use 3.14 for π

Answer 1

I'm going to assume the crust covered by the dosenot matter because the total surface area cannot be found without the depth of the pie.

So the surface are is the area of the top of the pie, the top of the pie is circular and is equal to 2$\pi$r²

The diameter is the sum of 2 radii, hence r=8

D=12
  = 2r =12
r=8

With the raduis the area can be found
A= 2$\pi$r²
A=2$\pi$8² 
A=2(64)$\pi$
A=128$\pi$

If the pie cost 10.99, the cost per inch can be found by dividing the area by cost

cost/inch =128 $\pi$/10.99
cost/inch =11.64$\pi$
               = 11.64(3.14)
               = 36.57

The pie costs 36 cents per square inch