Simple projectile motion, yet stuck.

[SigFig]

Homework Statement

A student threw a ball horizontally out a window 8.0m above the ground. It was caught by another student 10.0m away. What was the initial velocity of the ball?
ANSWER PROVIDED: 7.16m/s

Homework Equations

dv=1/2at^2
t=vv/a
dh=vht

The Attempt at a Solution

dv=1/2at^2
8=1/2(9.8)t^2
√ans
t=1.63sec

The fact that I'm trying to find it's initial velocity causes my brain to become a blank slate when deciding on what my next step should be (if the first is even right).

 

[SHISHKABOB]

is the other student supposed to be at ground level or something? What's the height which the ball is caught?