NEIEP Mechanics Practice Exam

How many cubic inches are in one gallon?

1. 128

2. 256

3. 231

4. 512

The correct answer is: 231

One gallon is equivalent to 231 cubic inches. This is based on the standard conversion of volume measurements in the United States, where a gallon is defined as a unit of measure for liquid capacity. To understand why 231 cubic inches is the correct volume for one gallon, it's essential to consider that the gallon is traditionally used to measure larger liquid volumes, and its equivalence in smaller units like cubic inches provides a clearer picture of its size. When looking at conversions between gallons and cubic inches, the ratio is derived from the specific definitions of these units. There are four quarts in a gallon, two pints in a quart, and two cups in a pint, leading ultimately to the cubic inch measurement. The 231 cubic inches reflects this measurement accurately, making it the standard accepted conversion used in various applications such as cooking, chemistry, and other scientific measurements that require precise volume calculations.