Question

Cost of milk when container is 16 cm high with radii 8cm and 20 cm at the rate of 50 rs per litre

Answer 1

Sol :

  h = 24 cm

lower end = r = 8 cm

upper end = R = 20 cm

V = (πh) / 3 x (R2 + Rr + r2)

                                      V = (π24) / 3 x (202 + 20x8 + 82)    

                                      V = 176 / 7 x 624

                                      V = 176 x 89.142 cm3

                                      V = 15688.992 cm3

                                     V = 15688.992 cm3 / 1000

                                      V = 15.688992 litre

Cost of milk per litre fill the container = 21 Rs

∴ Total cost of milk  fill the container = 15.688992 x21 = 329.4688rs