Find the $HCF(156, 455)$.

The Least Common Multiple $(LCM)$ of $7$,$11$,and $17$ is . . . . . . .

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

Every composite number greater than $1$ can be expressed (factorized) as a product of primes,and this factorization is . . . . . . apart from the order in which the prime factors occur. ($0$,$1$,unique)

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

The last digit of $5^n$ is . . . . . . ,where $n \in N$.