For a first order reaction A → B x= ____ min. (Nearest integer)

For a first order reaction $\displaystyle \mathrm{A} \rightarrow \mathrm{B}$

$\displaystyle \mathrm{t} /$ min	[A]/ M
$\displaystyle 0$	$\displaystyle 0.6500$
$\displaystyle x$	$\displaystyle 0.0650$
$\displaystyle 20$	$\displaystyle 0.00065$

$\displaystyle x=$ $\displaystyle \_\_\_\_$ min. (Nearest integer)