Help with Physics math!?

The tallest Sequoia sempervirens tree in California's Redwood National Park is 111 m tall. Suppose an object is thrown downward from the top of that tree with a certain initial velocity. If the object reaches the ground in 3.80 seconds, what is the objects initial velocity?



I don't know what formula to use on this. Please help?Help with Physics math!?
0=111+vo(3.8)+-4.9(3.8)^2 and solve

x=xo+vo(t)+ 1/2at^2



u know

x=0

xo=111

vo=??

v doesnt matter

a=-9.8

t=3.8



solveHelp with Physics math!?
s=ut+1/2at^2

111=ux3.8+1/2x-9.8 x 3.8^2

111=3.8u-4.9x14.44

3.8u=111-70.756

u=40.244/3.8

u=10.59m/s