How does the projectile always hit the target? [Help Please :]]?

It is because gravity is acting on both the projectile and target in the same way. They both fall at the same speed, no matter that the projectile is traveling laterally faster than the target. So at any point along the path that the target might be dropped the projectile will hit it because they are both falling at the same speed. Given enough distance, they would both hit the floor at the same time.