The formula for the volume and the area are V = (4/3)πr3 and A = 4πr2 respectively, where r = radius.
\The total volume of two spheres is 10π cubic units and the ratio of the areas is 4 : 9.
\Let V₁, A₁ and r₁ be the volume, area and radius of the smaller sphere, and V₂, A₂ and r₂ be the volume, area and radius of the larger sphere.
\From the information,
\V₁ + V₂ = 10π --------> (1)
\A₁ : A₂ = 4 : 9 --------> (2)
\First solve Equation 1 : V₁ + V₂ = 10π.
\(4/3)π(r₁)3 + (4/3)π(r₂)3 = 10π
\(4/3)π [(r₁)3 + (r₂)3 ] = 10π
\To find the radii of two spheres, solve equation 2 : A₁ : A₂ = 4 : 9.
\4π(r₁)2 : 4π(r₂)2 = 4 : 9
\(r₁)2 / (r₂)2 = 22 / 32.
\(r₁ / r₂)2 = (2 / 3)2.
\r₁ : r₂ = 2 : 3.
\Let r₁ = 2x and r₂ = 3x ⟹ (r₁)3 = 8x3 and (r₂)3 = 27x3.
\To find the value of x or x3, substitute values of r₁ = 2x and r₂ = 3x in the equation 1 : V₁ + V₂ = 10π.
\(4/3)π(2x)3 + (4/3)π(3x)3 = 10π
\(4/3)π(8x3)+ (4/3)π(27x3)= 10π
\(4/3)π(x3) [ 8 + 27] = 10π
\(4/3)π(x3) [35] = 10π
\x3 = 3/14.
\(r₁)3 = 8x3 ⟹ (r₁)3 = 8(3/14) ⟹ (r₁)3 = 12/7.
\(r₂)3 = 27x3 ⟹ (r₂)3 = 27(3/14) ⟹ (r₁)3 = 81/14.
\Volume of the smaller sphere V₁ = (4/3)π(r₁)3 = (4/3)π(12/7) = 16π/7 = 7.18 cubic units.
\Volume of the larger sphere V₂ = (4/3)π(r₂)3 = (4/3)π(81/14) = 54π/7 = 24.24 cubic units.
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