Question 974933

I fogot whole concept of real no of mie 9 standard ...i m in +2 bt i have a assignment to solve of my sis ...plz help me out.... Is  3√18 a rational or irrational no?
<pre>A square root is considered RATIONAL when the RADICAND is {{{highlight_green(0)}}}, or a {{{highlight_green(Perfect_Square)}}}