Classify the following numbers as rational or irrational with justification :
1. \(\sqrt{196}\) is
2. \(3\sqrt{18}\) is
3. \(\sqrt{\frac{9}{27}}\) is
4. \(\sqrt{\frac{28}{343}}\) is
5. \(-\sqrt{0.4}\) is
Answer variants:
a rational number
is an irrational number