Final answer:
The value that is irrational among the given options is 'π/19.' This is because pi (π) is an irrational number, and dividing it by an integer does not make it rational. All other options represent rational numbers.
Step-by-step explanation:
The question asks which value is irrational out of the given options. An irrational number is a number that cannot be written as a simple fraction - that is, it's not a ratio of two integers. Its decimal form does not stop and does not repeat. Let's evaluate the options:
- A. -6.7 - This is a decimal number that terminates, so it is not irrational.
- B. -6.7 - This is repeated, and it is the same as option A, still not an irrational number.
- C. π/19 - Pi (π) is an irrational number, and dividing it by an integer (19 in this case) does not make it rational. So, this is irrational.
- D. 25 - This is an integer, which is a type of rational number, so it is not irrational.
- E. 13.4 - This is also a decimal number that terminates, so it is not irrational.
Therefore, the answer is C. π/19, which is an irrational number.