In order to work on this one, we have to ignore air resistance.
If we include the effects of air resistance in our calculation, we would need
a ton of information that's not given in the question, and we would need an
Aeronautical Engineer to know how to use it all.
Ignoring air resistance . . .
Gravity adds 9.81 m/s to the downward speed of a falling object.
If the object is "dropped", then it's original speed is zero.
It reaches 117.72 m/s in
(117.72 m/s) / (9.81 m/sĀ²) = 12.00 seconds