$\sqrt{2}$ is a . . . . . . number. (Rational,Irrational,Prime)

Check whether $6^n$ can end with the digit $0$ for any natural number $n$.

The decimal representation of $44/625$ is . . . . . . (Terminating,Non-terminating repeating,Non-terminating non-repeating).

The $HCF$ of the smallest prime number and the smallest composite number is ........

Prove that $\sqrt{2}$ is irrational.

For two positive integers $a$ and $b$,if $\text{HCF}(a, b) = 7$ and $\text{LCM}(a, b) = 385$,then the product $a \times b$ is: