Solve the problem.
-A circular hole is filled with concrete to make a footing for a load-bearing pier. The hole measures 15 inches across and requires 1.9 bags of concrete in order to fill it to ground level. What is the
Depth of the hole? Round your answer to the nearest inch. (One bag of concrete, when mixed with
The appropriate amount of water, makes 1800 in.3 of material.)
A) 23 in.
B) 16 in.
C) 19 in.
D) 25 in.

Question

Quizplus · Accepted Answer

The volume of concrete required is 1.9 bags × 1800 in³/bag = 3420 in³. The volume of a cylinder (the hole) is given by V = πr²h, where r is the radius and h is the depth. The radius is half the diameter, so r = 15 in / 2 = 7.5 in. Rearranging the formula for volume to solve for h gives h = V / (πr²). Substituting the given values, h = 3420 in³ / (π * (7.5 in)²) ≈ 19.3 in, which rounds to 19 inches.

Solve the Problem. -A Circular Hole Is Filled with Concrete to Make a to Make