For any positive integer $n$,the last digit of $5^n$ is always . . . . . . .

How many decimal places are there in the decimal expansion of $\frac{3}{113}$?

Every positive even integer can be written in the form $4q + 2$.

If the Least Common Multiple $(LCM)$ of two numbers is equal to their product,then their Greatest Common Divisor $(GCD)$ is ........ .

For the decimal expansion of a rational number $\frac{p}{q}$ to be terminating,if $q = 2^m \cdot 5^n$,then $m, n \in$ . . . . . . ($R$,$N \cup \{0\}$,$Z$)

If the Least Common Multiple $(LCM)$ of $(12, 15, 21) = 500 + 2x$,then $x = $ . . . . . .