Let's classify each number:
-
Rational - A rational number can be expressed as the quotient of two integers.
- \( 3.\overline{8} \) (which can be expressed as \( \frac{38}{9} \))
- \( -\frac{11}{7} \)
- \( \sqrt{81} = 9 \) (since 9 is an integer)
-
Irrational - An irrational number cannot be expressed as a simple fraction.
- \( \pi \) (a well-known irrational number)
- \( 2\sqrt{2} \) (since \( \sqrt{2} \) is irrational, and multiplying an irrational number by a non-zero rational number is irrational)
Now, here's the classification:
Rational:
- \( 3.\overline{8} \)
- \( -\frac{11}{7} \)
- \( \sqrt{81} \)
Irrational:
- \( \pi \)
- \( 2\sqrt{2} \)