motion in straight line rain drop questions

1.Drops of water fall at regular intervals from
the roof of a building of height h = 16m.
The first drop striking the ground at the same
moment as the fifth drop is ready to leave from
the roof. Find the distance between the
successive drops.
2.A parachutist drops freely from an
aeroplane for 10 seconds before the parachute
opens out. Then he descends with a net
retardation of 2 m/s2
. His velocity when he
reaches the ground is 8 m/s. Find the height
at which he gets out of the aeroplane ?