$19.$ In a field pumping test the thickness of the formation to bedrock was $40$m and the groundwater

was $2$ m below the ground surface. At a pumping rate of $0\mathrm{.}20$ m$3/$s the water levels in two

observation wells, $10$ m and $30$ m from the pumping well experienced drawdowns of $3\mathrm{.}0$ m and

$2\mathrm{.}0$ m respectively. Determine the permeability.

a$.5\mathrm{.}60$ x $10-5$ m$/$s

b$.9\mathrm{.}85$ x $10-4$ m$/$s

c$.6\mathrm{.}22$ x $10-4$ m$/$s

d$.6\mathrm{.}87$ x $10-4$ m$/$s

$20.$ What will be the radius of influence of the problem in Q$19$ to the nearest metre?

a$.296$ m

b$.127$ m

c$.85$ m

d$.150$ m