I suppose down is negative in this problem
If you don't know why then you're in trouble, however that is in m/s so you have to convert to feet (which I forgot the conversion so you'll have to do it yourself)
This is what we're trying to find
Notice that they don't give time, so we'll use an equation without time.
The only one that comes to mind is:
So then we switch things around to get:
So substitute to get the answer