Physics problem (motion in one direction)?

Question

A stund woman sitting on a tree limb wishes to drop vertically onto a horse galloping under the tree. The speed of the horse is 10.0 m/s and the woman is initially 3.00 m above the level of the saddle. (a) What must be the horizontal distance between the saddle and limb when the woman makes her move? (b) how long is she in the air?