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At the park there is a pool shaped like a circle with diameter 22 yd. A ring-shaped path goes around the pool. Its width is 6 yd.
We are going to give a new layer of coating to the path. If one gallon of coating can cover 5 yd", how many gallons of coating do we need? Note that coating
comes only by the gallon, so the number of gallons must be a whole number. (Use the value 3.14 for n).

Respuesta :

calculista

Answer:

106 gal

Step-by-step explanation:

step 1

Find the area of the path

we know that

The area of the path is given by the formula

[tex]A=\pi r_2^{2} -\pi r_1^{2}[/tex]

[tex]A=\pi [r_2^{2} -r_1^{2}][/tex]

where

r_2 is the radius of the pool plus the width of the path

r_1 is the radius of the pool

we have

[tex]r_1=22/2=11\ yd[/tex] ---> the radius is half the diameter

[tex]r_2=11+6=17\ yd[/tex]

substitute

[tex]A=\pi [17^{2}-11^{2}][/tex]

[tex]A=168\pi\ yd^2[/tex]

assume

[tex]\pi =3.14[/tex]

[tex]A=168(3.14)=527.52\ yd^2[/tex]

step 2

Find the gallons of coating needed

Divide the area of the path by 5

so

[tex]527.52/5=105.5\ gal[/tex]

Round up

therefore

106 gal

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