Final answer:
The square root of 25 is 5, an integer, which means that /25 can be expressed as the fraction 5/1. Hence, /25 is a rational number because it can be expressed as a ratio of two integers.
Step-by-step explanation:
The number /25 refers to the square root of 25. To determine whether /25 is rational or irrational, consider if the square root yields a number that can be expressed as a fraction of two integers. The square root of 25 is 5, which is an integer and therefore can be expressed as the fraction 5/1. Hence, /25 is a rational number because it can be expressed as a ratio of two integers (5 and 1).
When checking the reasonableness of an answer in mathematics, it's important to consider the properties of numbers involved. For rational numbers, if the square root of a perfect square is found, it should be an integer and therefore rational. In this case, since 25 is a perfect square, /25 being an integer (5) makes the answer reasonable.