JAMB 2001 · UME · Q17

The identity element with respect to the multiplication shown in the table is

$\otimes$	$k$	$l$	$m$
$k$	$l$	$m$	$k$
$l$	$m$	$k$	$l$
$m$	$k$	$l$	$m$

Worked solution (try it first)

The identity leaves every element unchanged, so its row and column must repeat the headings $k, l, m$ .
The row for $m$ reads $k, l, m$ , and so does the column under $m$ .
So the identity is $m$ , option C.