"A ball is thrown up from the rooftop"

"A ball is thrown up from the rooftop with an initial speed of http://gauss.vaniercollege.qc.ca/web...fe94d858a1.png m/s. 1.84 s later, another ball is dropped from the rooftop.

a) Assuming that neither has landed, where and when do they meet?

m from the rooftop

at seconds from the moment the first ball was thrown.

b) What are their speeds when they meet?

The first ball : m/s

The second ball : m/s"

All my answers are wrong, except t = 2.065. I would appreciate it a lot if someone could help me do this question!

Thanks in advance!