$)$ For a falling head test, the following are given:

$$ length of specimen $=380$ mm;

$$ area of specimen $=6\mathrm{.}5$ cm$2$;

$$ k $=0\mathrm{.}175$ cm$/$min$.$

i$.$ What should be the area of the standpipe for the head to drop from $650$ cm to $300$ cm

in $8$ min?