GRE General TestQuantitative ReasoningMedium
A civil engineer is designing a sewage system. A cylindrical pipe has an inner diameter of 0.8 meters and a length of 50 meters. What is the volume of water (in cubic meters) that the pipe can hold when completely full? (Use \(\pi \approx 3.14\))
- A100.48 \(m^3\)
- B25.12 \(m^3\)
- C78.50 \(m^3\)
- D251.20 \(m^3\)
Show answer & explanationAnswer & explanation
Correct answer: B. 25.12 \(m^3\)
First, find the radius from the given diameter. Then, use the formula for the volume of a cylinder, V = \(\pi r^2 h\), with the calculated radius and given height (length).
Why the other options are wrong
- A. This results from using a different value for \(\pi\) or a slight miscalculation.
- C. This results from using the diameter as the radius in the formula.
- D. This results from using the diameter as the radius and potentially other errors.
Volume of a Cylinder
The volume of a cylinder is the amount of space it occupies, calculated by multiplying the area of its circular base by its height.
- Formula: V = \(\pi r^2 h\)
- r is the radius of the base, h is the height (or length) of the cylinder.
- Diameter is twice the radius (d = 2r).
Memory trick: Radius First, Then Pi-R-Squared-H: Find the radius, then apply the volume formula.