Projectile Problem

[rocky_xiii]

this question makes no sense to me.....

a cowboy drops from a balcony 25m high on to the back of his horse. If the horse is 5m high and is galloping past with a speed of 20m/s, where should the horse be when the cowboy releases his hold?

apartently the answer key says 40m...can someone tell me the equation :confused:

[faust9]

How long does it take for the cowbay to fall 20m? Knowing that time you should be able to position the horse accordingly.