Hi I have an exam next week and I will have a question similar to below that I need to...

Hi I have an exam next week and I will have a question similar to below that I need to answer with my working out. Please can some one show me how to do the following question so I can see how it's done.

Question: the height (s) meters of a mass projected vertically upwards at time (t) inseconds is s=it- 1/2gt^2

given that u=22ms^-1 and g=9.81ms^-2 determine how long the mass will take after being projected to reach a height of 16m on the ascent and the descent