The internal and external diameters of a hollow hemispherical vessel are 42 cm and 45.5 cm, respectively. Find its capacity and also its outer curved surface area.

Internal radius of a hollow hemispherical vessel (r₁) = 21 cm
External radius of a hollow hemispherical vessel (r₂) = 22.75 cm
Capacity of a hollow hemispherical vessel =π r₁³ = × × 21 × 21 × 21
                                                      = 19404 cm³
                                                      = 19.404 litres
Curved surface area of a hollow hemispherical vessel = 2π r₂²
                                                                     = 2× (22.75 ) ²
                                                                     = 3253.25 cm³.