How Tall Was the Initial Fall in a Physics Problem?

[ryno2107]

A freely falling object requires 1.10 s to travel the last 20.0 m before it hits the ground. From what height above the ground did it fall? (Ans. in m.)

I am completely lost on modeling this problem. Please help me figure it out.

 

[Delphi51]

The model is just accelerated motion so you have the usual
V = Vi + at and d = Vi*t + .5*a*t^2 to work with.
Looks like you don't have enough info to use the first one, but the second one can be used to get the Vi - the velocity at height 20 m.
That's a good start. Then you can use the first equation to found out when the velocity was zero.