How much time does it take for the bill to fall beyond her grasp? the length of a bill is 16 cm?

Distance = 0.5 x g x t^2 where g is the gravitational force and t is the time required to cover the mentioned distance.

we have g = 9.8 m/sec^2 and distance = 16 cm = 0.16 m

From the above mentioned equation:

t = (2s / g) ^0.5

Substituting with the givens, we can calculate t as follows:

t = [ (2 x 0.16) / 9.8]^0.5 = 0.1807 seconds