Question

a tent is in the shape of right circular cylinder upto a height of 3M and conical above it .the maximum height of the tent above ground is 13.5 m.calculate the cost of painting the inner side of the tent at the rate of 3 rupees per sq m if radius of base is 14 m.​

Answer 1

Height of Cylinder = 3 m

Radius of Cylinder = 14 m

CSA of Cylinder = 2πrh

                          $= \frac{22}{7} * 14 * 2 *3\\\\=264m^2$

Height of Cone = 13.5 - 3

                         = 10.5 m

Radius of Cone = 14 m

$l^2=h^2+r^2$

$l^2= (14)^2+ (10.5)^2\\\\l^2 = 306.25\\\\l = \sqrt{306.25}\\\\ l= 17.5 m$

CSA of Cone = πrl

                      $=\frac{22}{7}*14*17.5\\ \\=770m^2$

Total Area = 264 + 770

                 = 1034 m²

Cost of cloth per square meter = Rs 3

                                                   = 1034 × 3

                                                  = 3102