Question

the total surface area of a solid right circular cylinder is 1540 m square . if its hieght is four times the radius of the base ,then find the h of the cylinder

Answer 1

Given that TSA of a cylinder = 1540 m^2.  and h = 4r ----- (1)

                     2 * pr * r(h + r) = 1540

                     2 * 22/7 * r(4r + r) = 1540 (Given that height is 4 times of radius)

                    2 * 22/7 * 5r^2 = 1540
 
                    44/7 * 5r^2 = 1540

                     r^2 = 49

                    r = 7cm.

Substitute r in (1), we get

Height h of the cylinder = 4 * r

                                         = 28 cm.

Hope this helps!