You need to use the kinematic equations (commonly called SUVAT equations.)
The method is always the same:
Draw a sketch showing what you know, not to scale, just showing the directions of any acceleration, velocity etc. given in the question.
List the factors s, u, v, a, t vertically and write in their values with units. Put an question mark next to the one you need to find and a dash next to any that are irrelevant.
Select the equation that contains the variables you know and the one you're looking for. Remember you always know the acceleration on Earth, g taken as being 9.81
#ms^-2#. Other planets/moons will have a value given. The full list of equations is given here: http://www.physicsclassroom.com/class/1DKin/Lesson-6/Kinematic-Equations
Substitute in your values.
Find the answer and don't forget your units!
I get 46 m and 3.1 s (to 2 s.f.)
Finally, you need to be aware of the language used (words like dropped, at rest, thrown, stops etc. tell you additional details about the velocities that are not obvious when starting out.)