Answer
0.99 m/s.
Work Step by Step
The momentum in the horizontal direction will be conserved. Let the positive direction be the direction in which the bullet was originally moving.
$$ (0.022 kg)(240 m/s) + 0 = (0.022 kg)(150 m/s) + (2.0 kg)v$$
Solve for velocity v = 0.99 m/s, rounded to 2 significant figures.