Determining the Height of a Building

Homework Statement

You are sitting by a window when someone on the roof drops a ball. The ball spends .30 seconds in front of the window (which is 1.50 meters tall.) The ball subsequently hits the sidewalk and bounces back up at the same speed. On its way up it passes by the window again taking .30 seconds in front of the window. If the ball spends 2.50 seconds underneath the window then how tall is the building?

Homework Equations

$\Delta x = v_{0}t+(1/2)at^{2}$

The Attempt at a Solution

I have absolutely no idea how to approach this problem. I would appreciate any help.