PHYSICS
posted by Happy FacePLZ HELP!! .
Harry and Angela look from their balcony to a swimming pool below that is 15 m from the bottom of their building. They estimate that the balcony is 45 m high and wonder how fast they would have to jump horizontally to succeed in reaching the pool. What is the answer?
Please Help!!
Thanks! :)

how do you do this problem?
i don't get it...please help! 
What formula should i use for this problem, please help!
Thanks