Answer:
the volume of sand is 
Step-by-step explanation:
This problem bothers on the mensuration of solid shapes, rectangular prism.
Given data

if the sandbox is filled with sand of
deep the volume of the sand in the box will be calculated based on the the depth of the sand
converting the depth of sand from mixed fraction to proper fraction we have 
the expression for the volume of a rectangular prism is

substituting our data into the expression we have

I’m pretty sure it is B
Hope I helped.
Answer:
= x
Step-by-step explanation:
In right triangles the sum of square length of two legs is equal to square length of hypotenuse:
7^2 + 8^2 = x^2
49 + 64 = x^2 add like terms
113 = x^2 find the root for both sides
= x