Problema Solution
A can of beans has surface area 302^2. Its height is 12 cm. What is the radius of the circular​ top? (Hint: The surface area consists of the circular top and bottom and a rectangle that represents the side cut open vertically and​ unrolled.)
Answer provided by our tutors
The can of beans is a cylinder.
H = 12 cm
A = 302pi cm^2
R = the radius of the circular top
A = 2*R^2*pi + 2*R*pi*H
2*R^2*pi + 2*R*pi*H = A
2*R^2*pi + 2*R*pi*12 = 302pi
2R^2 + 24R - 302 = 0 divide both sides by 2
R^2 + 12R - 151 = 0
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click here to see the equation solved for R
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R = 7.67 cm approximately
The radius of the circular top is 7.67 cm approximately.