According to Euclid's division lemma,for $a$ and $5$,if $a = 5q + r$ is unique,then $r = \ldots$ is not possible.

Euclid's division lemma states that for two positive integers $a$ and $b,$ there exist unique integers $q$ and $r$ such that $a = bq + r,$ where $r$ must satisfy

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

Prove that $\sqrt{p}+\sqrt{q}$ is irrational,where $p$ and $q$ are distinct prime numbers.

Find the $\text{l.c.m.}$ and $\text{g.c.d.}$ of the following by using the fundamental theorem of arithmetic: $84$,$90$,and $120$.

The pair .......... is a like surds.