jmc

Question

The height of a right cylinder is 2.5 times its radius. If the surface area of the cylinder is 112 cm^2, what is the radius of the cylinder in centimeters?

Accepted Answer

The surface area of a cylinder with radius r and height h is 2 r^2+2 rh. Setting this expression equal to 112 and substituting h=2.5r gives align* 2 r(r+2.5r) &= 112 7 r^2 &= 112 r^2 &= 16 r&=4 cm. align*