Answer
The magnetic force is $7.2 \times 10^{-21}~N$ and this force is directed into the page.
Work Step by Step
We can find the magnetic force:
$F = q~v\times B$
$F = (-8.0\times 10^{-18}~C)(0.30\times 10^{-2}~m/s)(0.30~T)$
$F = -7.2 \times 10^{-21}~N$
By the right hand rule, $v \times B$ would be directed out of the page if the charge was positive. However, the negative charge results in a force directed into the page.
The magnetic force is $7.2 \times 10^{-21}~N$ and this force is directed into the page.
