Question

The internal and external diameters of a hollow hemispherical vessel are 24 cm and 25 CM respectively. if the cost of painting 1 cm of the surface area is 0.05 find the total cost of painting the vessel all over

Answer 1

Answer:15.4

Step-by-step explanation:

let the internal radius be r=24cm

let the external radius be R=25cm

surface area of hemisphere = 2 pi radius square

surface area of hemispherical vessel = surface area of external hemisphere - surface area of internal hemisphere

= 2 pi R^2 -2 pi r^2

=2 pi (R^2-r^2)

=2 . 22/7 ( 25^2 - 24^2)

=2.22/7.49

=308 cm sq

1 cm sq = 0.05

308cm sq= 308 . 0.05= 15.4