Answer
The bullet of mass m has a greater speed by a factor of $\sqrt{2}$.
Both bullets do the same amount of work, because they are starting with the same amount of kinetic energy.
Work Step by Step
Let the masses of the two bullets be m and 2m.
The kinetic energy of the two bullets is equal.
$\frac{1}{2}(m)(v_1^2) = \frac{1}{2}(2m)(v_2^2)$
$v_1^2 = 2v_2^2$
$v_1 = \sqrt{2}\times v_2$
The bullet of mass m has a greater speed by a factor of $\sqrt{2}$.
Both bullets do the same amount of work, because they start with the same amount of kinetic energy.
