$17.$

In a field pumping test the thickness of the formation to bedrock was $30$m and the groundwater was $3$ m below the ground surface. At a pumping rate of $\mathrm{.}0\mathrm{.}015$ m$3/$s the water levels in two observation wells, $15$ m and $30$ m from the pumping well, measured from the surface were $8\mathrm{.}0$ m and $6\mathrm{.}0$ m respectively. Determine the permeability.

a$.$

$4\mathrm{.}60$ x $10-5$ m$/$s

b$.$

$6\mathrm{.}85$ x $10-4$ m$/$s

c$.$

$6\mathrm{.}22$ x $10-5$ m$/$s

d$.$

$3\mathrm{.}60$ x $10-5$ m$/$s

$18.$

What will be the radius of influence of the problem in Q$17$ to the nearest metre

$($a$)$

$200$ m

$($b$)$

$85$ m

$($c$)$

$95$ m

$($d$)$

$150$ m$?$