Two bullets are fired simultaneously and horizontally from the same...

The vertical motion of a projectile is independent of its horizontal motion.

For both bullets, the initial vertical velocity is zero ($u_y = 0$).

Using the equation of motion for the vertical direction, $h = u_y t + \dfrac{1}{2} g t^2$.

Since $u_y = 0$, the time taken to reach the ground is $t = \sqrt{\dfrac{2h}{g}}$.

As both bullets are fired from the same height $h$ and experience the same acceleration due to gravity $g$, the time of flight $t$ is the same for both.

Therefore, both bullets will reach the ground simultaneously.