PLEASE HELP ME WITH 11 QUESTIONS BELOW!! THANK YOU

1. index of [tex]\sqrt[4]{20}[/tex]
2. index of [tex]\sqrt{15}[/tex]
3. radicand of [tex]\sqrt[8]{21}[/tex]
4. [tex]\sqrt[3]{5^{4} }[/tex]
5. [tex]\sqrt[7]{x^{2} }[/tex]
6. [tex]\sqrt{b^{9} }[/tex]
7. [tex]\sqrt[3]{125}[/tex]
8. [tex]\sqrt[3]{n^{21} }[/tex]
9. [tex]\sqrt[5]{a^{20} }[/tex]
10. [tex]\sqrt{81p^{10} }[/tex]
11. [tex]\sqrt[6]{a^{18} b^{12} }[/tex]