Select the correct answer.

Which number is an irrational number?

A. [tex]\sqrt{100}[/tex]
B. [tex]\frac{1}{8}[/tex]
C. -2.2675
D. [tex]\sqrt[3]{16}[/tex]



Answer :

Certainly! Let's go through each option one by one to determine whether it's rational or irrational.

1. Option A: [tex]\(\sqrt{100}\)[/tex]

[tex]\[ \sqrt{100} = 10 \][/tex]

The square root of 100 is 10, which is an integer. An integer is a rational number because it can be expressed as the fraction [tex]\(\frac{10}{1}\)[/tex].

2. Option B: [tex]\(\frac{1}{8}\)[/tex]

[tex]\[ \frac{1}{8} = 0.125 \][/tex]

The fraction [tex]\(\frac{1}{8}\)[/tex] is a rational number because it is a ratio of two integers (1 and 8) and can be expressed as a terminating decimal, 0.125.

3. Option C: [tex]\(-2.2675\)[/tex]

[tex]\[ -2.2675 \][/tex]

The number [tex]\(-2.2675\)[/tex] is a finite decimal. Finite decimals are rational because they can be written as a fraction. For instance, [tex]\(-2.2675\)[/tex] can be expressed as [tex]\(-\frac{22675}{10000}\)[/tex].

4. Option D: [tex]\(\sqrt[3]{16}\)[/tex]

[tex]\(\sqrt[3]{16}\)[/tex] is the cube root of 16. To determine if it's rational or irrational, consider whether it can be written as a fraction or has a terminating or repeating decimal representation.

The cube root of 16 is not a nice integer value and cannot be expressed as a simple fraction. Its decimal representation is non-terminating and non-repeating. Therefore, it is an irrational number.

After examining all the options, we see that:

- Option A is rational.
- Option B is rational.
- Option C is rational.
- Option D is irrational.

Hence, the correct answer is:

[tex]\[ D. \sqrt[3]{16} \][/tex]