Answer
$E=12K\frac{N}{C}$
Work Step by Step
We can calculate the electric field at the sphere as:
$E=K\frac{q}{r^2}$
We plug in the known values to obtain:
$E=9\times10^9\times\frac{3\times 10^{-8}}{{(0.15)^2}}$
$E=1.2\times10^4$
$E=12K\frac{N}{C}$
