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A cylinder tube with caps on both ends is used to safely carry a rolled up poster. The tube is 42 inches tall with a radius of 1.5 inches. If one mini can of spray paint covers 150 square inches, how many mini spray cans of red paint would be needed to cover the entire tube?

A. 3
B. 2
C. 1
D. 4

If anyone know this kind of math, I really need help with it. Im not very good in math and I have testing coming soon. Thanks!

Respuesta :

apologiabiology
find surface area
SA=2pir^2+2hpir

h=42
r=1.5

SA=2pi1.5^2+2(42)pi1.5
SA=4.5pi+126pi
SA=130.5pi square inches


area/areacoverdperspray≤numberofsprays
130.5pi/150
2.73
so buy 3 cans because you can't get 0.73 cans

A

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