Motion in a straight line

A ball is thrown vertically
upwards with a velocity of 20 m s–1 from
the top of a multistorey building. The
height of the point from where the ball is
thrown is 25.0 m from the ground. (a) How
high will the ball rise ? and (b) how long
will it be before the ball hits the ground?
Take g = 10 m s–2
.