PLS HELP A sand castle can be modeled with four 6-inch-tall square prisms, one on top of the other, as shown in the figure below.

The base of the bottom prism has a side length of 30 inches, and the base of each of the other three prisms has a side length 7 inches less than the side length of the base of the prism below it. What is the volume of the sand castle?
5,196 square inches
7,422 square inches
10,596 square inches

10,596 cubic inches

Step-by-step explanation:

The shape of the prism with which the sand castle can be modelled = Square prism

The arrangement of the square prism = One on top of the other

The given height of each prism, h = 6 inches

The side length of the base of the bottom prism, s₄ = 30 inches

The side length of the base of the other prism = The side length of the base of the prism below each prism - 7 inches

Therefore;

The side length of a prism = 7 inches + The side length of the prism above it

Given that the side length of the base prism (The fourth prism), s₄ = 30 inches

The side length of the prism, directly above the base prism (The fourth prism), s₃ = (30 - 7) inches = 23 inches

The side length of the prism, directly above the third prism (The second prism), s₃ = (23 - 7) = 16 inches

The side length of the top most prism, s₁ = (16 - 7) inches = 9 inches

The volume of the sand castle, V = h × (s₄² + s₃² + s₂² + s₁²)

∴ V = 6 × (30² + 23² + 16² + 9²) = 10,596

The volume of the sand castle, V = 10,596 in.³

7 ft 6 in means 7 1/2, because 6 in is 1/2 of a foot. 7 ft 8 in means 7 2/3 because 8 in is 2/3 of a foot. 23/3 = 7 2/3. 15/2 = 7 1/2.

23/3   *   15/2   = 57 1/2

step-by-step explanation: