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:

If $p$ and $q$ are distinct prime integers,then their Least Common Multiple $(LCM)$ is . . . . . . .

By using the fact $g.c.d. (a, b) \times l.c.m. (a, b) = a \times b$,find $l.c.m. (26, 91)$.

If $HCF(p, q) = p$,then $LCM(p, q)$ is equal to . . . . . . .

Find the $\text{g.c.d.}$ and $\text{l.c.m.}$ of $72$ and $90$ using the fundamental theorem of arithmetic.

Without actually performing the long division,state whether the following rational number will have a terminating decimal expansion or a non-terminating repeating decimal expansion: $\frac{77}{210}$.