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

The Least Common Multiple $(LCM)$ of the smallest prime number and the smallest composite number is . . . . . . .

Without performing long division,state whether the decimal expansion of the rational number $\frac{13}{3125}$ is terminating or non-terminating repeating.

Find the $HCF$ of $12, 15$,and $21$.

Express the number $5005$ as a product of its prime factors.

The $HCF$ of two numbers is $9$ and their product is $288$. Find their $LCM$.