Projectile Motion Problem

I r confused. Help is needed.
An arrow is shot at 45 degrees at 125 meters/second. It pops a balloon at the peak of its flight. What is the velocity of the arrow as it hits the balloon?

at the peak of its flight, its y-velocity equals 0. (it's at the maximum height, so the slope (equal to velocity) on a y-distance vs time graph would be 0).

First split it into x and y components.

Vx = V cos theta
Vy = V sin theta

Because Vy is 0 at the peak of its flight, the velocity is only its x component.

Vx = 125 cos 45