Match the number with the correct description.(5 points) Rational or irrational and why?

101−−−√
0.424242424...
0.133134135...
16−−√
0.789

1 answer

Let's match each of the given numbers with its correct description (rational or irrational) and explain why.

  1. \( \sqrt{101} \)

    • Description: Irrational
    • Why: \( \sqrt{101} \) cannot be expressed as a fraction of two integers because 101 is not a perfect square, and its decimal representation is non-repeating and non-terminating.
  2. 0.424242424...

    • Description: Rational
    • Why: This number has a repeating decimal (the "42" repeats), which can be expressed as a fraction (specifically \( \frac{42}{99} \)).
  3. 0.133134135...

    • Description: Irrational
    • Why: The decimal appears to be non-repeating and non-terminating. As such, it cannot be expressed as a fraction of two integers.
  4. \( \sqrt{16} \)

    • Description: Rational
    • Why: \( \sqrt{16} = 4 \), which is an integer and can be expressed as a fraction (\( \frac{4}{1} \)).
  5. 0.789

    • Description: Rational
    • Why: This number has a finite decimal representation, which can be expressed as a fraction (\( \frac{789}{1000} \)).

To summarize:

  • \( \sqrt{101} \): Irrational
  • 0.424242424...: Rational
  • 0.133134135...: Irrational
  • \( \sqrt{16} \): Rational
  • 0.789: Rational