A gun that shoots bullets at 469m/s is to be aimed at a target 45.7 m away ans level with the gun. How high above the target must the gun barrel be pointed so that the bullet hits the target?

Which equation would I use?

I should have gotten 4.8 cm for the answer...

Find the time it takes to travel that distance:
distance=velocity*time

Then, how far will the bullet drop in that time?

distancefell=1/2 g time^2