Solution:
A few definitions...
- Rational number - Any integer, fraction, terminating decimal, or repeating decimal is classified as a rational number
- Irrational number - All the real numbers which are not rational numbers.
Option A - Rational or Irrational?
Since both are known as fractions, they are rational numbers.
Option B - Rational or Irrational?
√2 is classified as an Irrational number because if it is simplified, it does not result in any integer, fraction, terminating decimal, or repeating decimal.
Option C - Rational or Irrational?
- 1/√4 + 7/2
- => 1/2 + 7/2
- => 8/2 = 4
Since this is an integer, this is rational.
Option D - Rational or Irrational?
- √9 + √4
- => √3 x 3 + √2 x 2
- => 3 + 2 = 5
Since this is an integer, this is rational.
In conclusion...
Option B is correct.