Marbles rolling down the ramp and horizontally off your desk consistantly land 72.0 cm from the base of your desk. Your desk is 77.0 cm high. If you pull your desk over to the window of your second story room and "launch" marbles to the ground (6.28 meters below the desk top), how far out into the yard will the marbles land?

The time it takes to hit is t, where

4.9t^2 = 0.77
t = 0.396s
so the horizontal speed is 0.72/0.396 = 1.816 m/s

The time it takes to fall 6.28m is
4.9t^2 = 6.28
Using that value of t, the marbles will land 1.816t m away