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If the height of the cylinder is 10 inches, and the surface area is 200 sq. inches, determine the length of the radius

The formula for the surface area of a cylinder is: A=2pirh+2pir^2

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SURENDRA K. | An experienced,patient & hardworking tutorAn experienced,patient & hardworking tut...
2*pi*r*h +2*pi*r^2=  200
2*pi*r*10 + 2*pi*r ^2=200
20*pi*r +2*pi*r^2= 200
Solving this quadratic equation using
Roots are = (-b+-sqrt(b^2-4ac))/2a
r= 2.53 inches
So, radius = 2.53 inches


I have put this answer in several times and it says that it is incorrect. That is the answer that I got as well.